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Fertility and aging: do reproductive-aged Canadian women know what they need to know?
INFERTILITY Fertility and aging: do reproductive-aged Canadian women know what they need to know? Karla L. Bretherick, Ph.D.,a,b Nichole Fairbrother, Ph.D.,b,c Luana Avila, B.Sc.,a,b Sara H. A. Harbord, M.Sc.,a,b and Wendy P. Robinson, Ph.D.a a
Department of Medical Genetics, University of British Columbia, Vancouver; b Interdisciplinary Women’s Reproductive Health Research Training program, Child and Family Research Institute, Vancouver; and c Women’s Health Research Institute, BC Women’s Hospital and Health Centre, Vancouver, British Columbia, Canada
Objective: Female fertility declines with age; however, women are increasingly delaying childbearing until later in their reproductive years. One of the factors that may contribute to this trend is a general lack of knowledge about the decline in fertility with age. Design: Self-report survey. Questions pertained to participant demographics and childbearing intentions, and knowledge of the decline in fertility and increased risk of pregnancy loss with age. Setting: The University of British Columbia in Vancouver, British Columbia, Canada. Patients: Female undergraduate students (N ¼ 360). Intervention(s): None. Main Outcome Measure(s): Knowledge of fertility over the life span, predictors of age of intended childbearing. Result(s): Although most women were aware that fertility declines with age, they significantly overestimated the chance of pregnancy at all ages and were not conscious of the steep rate of fertility decline. Surprisingly, women overestimated the chance of pregnancy loss at all ages, but did not generally identify a woman’s age as the strongest risk factor for miscarriage. Conclusion(s): Education regarding the rate at which reproductive capacity declines with age is necessary to avoid unintended childlessness among female academics and professionals. (Fertil Steril 2010;93:2162–8. 2010 by American Society for Reproductive Medicine.) Key Words: Women, knowledge, fertility, aging, education, survey
In the past few decades there has been a noticeable trend among women in many parts of the developed world to delay childbearing until relatively late into their reproductive years. For example, in the Canadian province of British Columbia, the proportion of first time mothers who are over the age of 30 has increased steadily from <7% in 1968 to 44% in 2005 (1). Moreover, the number of first-time mothers over the age of 35
Received August 13, 2008; revised December 19, 2008; accepted January 7, 2009; published online March 17, 2009. K.L.B. has nothing to declare. N.F. has nothing to declare. L.A. has nothing to declare. S.H.A.H. has nothing to declare. W.P.R. has nothing to declare. The first two authors contributed equally to this work. Supported by a grant from the Interdisciplinary Women’s Reproductive Health Training Program at the Child and Family Research Institute, Vancouver, British Columbia, Canada, awarded to Dr. Karla Bretherick and Dr. Nichole Fairbrother. The present address for Dr. Fairbrother is Genome Sciences Centre, BC Cancer Agency, Vancouver, British Columbia, Canada. This article was presented at the Canadian Fertility and Andrology Society 52nd annual meeting, Ottawa, Ontario, Canada, November 15–18, 2006. Reprint requests: Karla L. Bretherick, Ph.D., BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3 Canada (FAX: 604-674-8178; E-mail: [email protected]).
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was nearly 15% in 2005. This trend was first noted >20 years ago (2) and is now prevalent in Canada (3, 4), Europe (5), Australia (6), and the United States (7). What is less publicized, however, is the number of women who fail to achieve a successful pregnancy because of unanticipated problems associated with an age-related decline in fertility. Are young adults today aware of the risks they may be taking when they decide to delay reproduction until they are past their prime fertility? The age-related decline in fertility is attributable to both a decrease in conception rates and an increase in pregnancy loss rates. This decline begins at around age 30 (8), and accelerates after age 35, such that fertility is close to zero by the time a woman reaches age 45 (9). The decline in fertility with age is a result of a reduction in the quantity and quality of oocytes (10–12), which also leads to decreased success in achieving pregnancy by in vitro fertilization (IVF) when using a woman’s own eggs; for a review of this topic, see Marcus and Brinsden (13). In addition, pregnant women at an advanced maternal age also face an increased risk of pregnancy complications such as primary Caesarean delivery, prolonged and dysfunctional labor, pregnancy hypertension, and delivery before 32 weeks (14).
Fertility and Sterility Vol. 93, No. 7, May 1, 2010 Copyright ª2010 American Society for Reproductive Medicine, Published by Elsevier Inc.
0015-0282/10/$36.00 doi:10.1016/j.fertnstert.2009.01.064
Multiple factors, such as waiting for a stable relationship and a desire for professional independence and financial security, have been found to contribute to a woman’s decision to postpone parenthood (3, 5, 6, 15). Female university students in particular, are a group that is likely to delay childbearing in their quest for professional, academic, and career training (5, 7). These women may postpone reproduction because of concerns about the potential negative impact of starting a family on career advancement, and a lack of knowledge concerning the decrease in fertility with age. Indeed, 19% of childless women surveyed at an IVF clinic reported the desire for a career as the reason for having postponed pregnancy, and 18% reported being unaware of the impact of age on fertility (6). Myths about the chances of successful childbearing late in one’s reproductive life, and the social acceptability of delayed parenthood are perpetuated by a media bias in presenting success stories of births to women after age 40, and a lack of discussion about the assisted reproductive technology measures often required to achieve such pregnancies (16). Although knowledge of aging and fertility has been assessed in new mothers (17), women seeking infertility treatments (6, 18, 19), and medical personnel (20), there has been limited study of university women, a population in which this knowledge may be particularly relevant. To our knowledge, three previous studies, all of which were based in Sweden, have assessed knowledge of reproductive aging among university students: [1] a survey of attitudes toward parenting among women attending a university student health center revealed that students understand the association between age and fertility, but overestimate the probability of achieving pregnancy at the time of ovulation, and underestimate age as a factor in infertility (5); [2] a study of undergraduate student’s knowledge of age-related fertility issues found that many students underestimated the effect of age on fertility (21); and [3] a study of female graduate students further supported these findings (22). To date, there has been no assessment of university women in any country other than Sweden regarding knowledge of age-related fertility issues including the impact of aging on likelihood of conception, frequency of infertility, incidence of pregnancy loss, and rate of IVF success. To assess university women’s knowledge of fertility and aging, we developed and administered a survey to female undergraduate students at the University of British Columbia in western Canada. The objective of this project was to illuminate the level of understanding of reproductive aging women in this group possess. In particular, the following hypotheses were proposed: [1] reproductive-aged university women overestimate the chance of pregnancy as they age, [2] reproductive-aged university women underestimate the risk of pregnancy loss as they age, and [3] knowledge of fertility over the life span will predict the age at which female undergraduates intend to bear their first child, over and above the contribution of the woman’s current age, marital status, career plans, field of study, number of desired chilFertility and Sterility
dren, and her mother’s age at the time of first childbearing. To our knowledge, this is the first Canadian survey of university women’s knowledge of fertility and aging. Survey findings highlight the educational needs of this group of women, and can act as the basis for instructive campaigns in this area. METHODS Participants Surveys were administered to 405 female volunteers at the University of British Columbia (UBC) Vancouver campus. To obtain a homogeneous sample and to facilitate understanding of the knowledge and intentions of a specific female population, surveys in which the volunteer was not enrolled in a UBC undergraduate program (n ¼ 45) were excluded before data analysis. Excluded surveys included those completed by graduate and professional students (n ¼ 33), visiting students (n ¼ 3), university staff (n ¼ 3), and those for which student status was not reported (n ¼ 6). The remaining surveys (89%) were completed by 360 female undergraduate students representing approximately 2% of the total female undergraduate students enrolled at this campus. Participants ranged in age from 18 to 42, with a mean age of 21.28 years (SD ¼ 2.81), reflecting the UBC population in which 74% of undergraduate students are between 18 and 24 years of age. Most participants were single (88.8%), and Caucasian (52.0%) or Asian (29.9%). Participants’ primary fields of study represent a broad range of disciplines, including arts (24.4%), social sciences (23.2%), health sciences (21.8%), basic sciences (19.1%), applied sciences (3.6%), business (3.4%), agricultural sciences (2.5%), education (0.8%), and others (1.1%). Most participants reported being in their first 4 years of undergraduate study (90.6%) with a small number being in their fifth year of study (9.4%). Measures The Reproductive Health Survey was developed for the purposes of this research and contained questions pertaining to the following: demographic information (5 items), family information and childbearing intentions (4 items), fertility and infertility (10 items), pregnancy loss (4 items), and assisted reproductive technologies (1 item). A multiple-choice response format was used for most the survey questions. For questions regarding knowledge of the likelihood of an event, a scale of from 0 to 100% in 10% increments was presented, and participants were asked to circle their response. For questions regarding time required for an event, a scale of 0 to 20 in 2-month increments was presented. A small number of the demographic and family background questions used an open-ended response format (e.g., race/ethnicity, mother’s age when she bore her first child). The survey required approximately 20 minutes of the participant’s time to complete. Survey questions were compiled collaboratively by the investigators, representing the fields of psychology (survey development) and medical genetics (fertility and aging). Feedback from other investigators who are knowledgeable in the area of 2163
TABLE 1 Descriptive data concerning fertility over the life span. Survey item
%
1. Which of the following is the strongest risk factor for infertility? The woman’s agea Physical or emotional stress Exposure to cigarette smoke Long term use of the birth control pill 2. Which of the following scenarios most accurately describes a woman’s fertility over her lifetime? Fertility significantly drops off more than a decade prior to menopausea Fertility stays about the same from the onset of menstruation until menopause Fertility increases with age from the onset of menstruation until menopause Women remain fertile even several years after menopause 3. Which is the strongest risk factor for miscarriage? Physical or emotional stress The woman’s agea Exposure to cigarette smoke Strenuous exercise during pregnancy Long-term use of the birth control pill 4. A 40-year-old woman undergoing in vitro fertilization has the best chance of becoming pregnant when using: In vitro fertilization success does not depend on origin of eggs Her own eggs Eggs donated by a 20-year-old donora Eggs donated by a close female relative a
46.0 25.9 19.0 9.2
70.3 20.1
6.5
3.1
47.7 24.7 14.5 9.7 3.4
43.1 36.3 15.2 5.4
Correct response according to published literature.
Bretherick. Fertility and aging knowledge survey. Fertil Steril 2010.
survey development and life span fertility was sought and used to modify the initial version. Following this initial development, the survey was piloted with a small number of reproductive-aged university women and modified to incorporate their feedback. The final version of the survey was administered to participants. Correct responses for multiple choice questions were compiled from a number of sources (23–27) and are indicated by bold lettering in Table 1. For responses in Table 2, we com2164
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pared the sample mean response with the known population mean using one-sample t tests. Population means described in the literature (24, 26–28) are not entirely concordant with one another, but span a narrow range of values. To reduce the likelihood of incorrectly assigning significance where in fact no difference exists (type 1 error), the population value on the end of the range that differed least from the sample mean was used for each statistical analysis. To test the hypothesis that knowledge of fertility over the life span will predict the age at which reproductive aged women intend to bear their first child, we created a composite knowledge of fertility over the life span score based on responses to items 1 and 2 on Table 1, and items 1 and 2 on Table 2. In addition, participants were also given two trend scores based on items 1 (i.e., ‘‘What is the chance that a 20-, 30-, and 40-year-old woman will become pregnant after 1 month of regular unprotected sex?’’), and 2 (‘‘How many months does it take for the average 20-, 30-, and 40year-old woman to become pregnant if she is having regular unprotected sex?’’) in Table 2. This means that even if a woman underestimated or overestimated the effect of aging on the probability of achieving pregnancy, if she appreciated the direction of this effect (i.e., that the chances of achieving pregnancy decline as one ages), she was given a point for this. Responses to the eight survey questions and the two trends were scored on a 0 to 1 scale, with 0 for a fully incorrect response and 1 for a fully correct response. A score of 0.5 was given in instances where a partially correct response was given. This scoring system resulted in a knowledge score with a possible range of 0 to 10. Scores on the composite knowledge scale spanned the full range of possible scores (i.e., from 1 to 10) with a mean of 4.13 (i.e., 41% correct), and a standard deviation of 2.09. Procedures Participants were recruited in public locations across the Vancouver campus of the UBC between February 2, 2006 and April 19, 2006. Participants who voluntarily responded to a poster advertisement at the survey table completed the Reproductive Health Survey and the project consent form under the supervision of a survey administrator. As volunteers were self-selected, we are unable to determine the response rate of the target sample. Participants returned the survey and were given a small food item and a fact sheet pertaining to fertility and aging in appreciation for their time and effort. Fact sheets included information on the decline in monthly chance of pregnancy with age, the average age and decline in fertility preceding menopause, the incidence of infertility and miscarriage according to age, and the success rates of in vitro fertilization at various ages. Surveys were filled out anonymously and confidentially, identified only by date of administration and birth date, and assigned a survey number upon entry of data into the project database. Approval for the project was obtained from the Behavioral Research Ethics Board of the UBC (approval number B05-0832). The investigators declare no conflict of interest in this research. Vol. 93, No. 7, May 1, 2010
TABLE 2 Comparison of mean participant responses to population estimates. Participant Population response mean (SD) meana
Survey item 1. What is the chance (%) that after 1 month of regular unprotected sex a: 20-year-old woman will become pregnant? 30-year-old woman will become pregnant? 40-year-old woman will become pregnant? 2. How many months of regular unprotected sex does it take for the average: 20-year-old woman to become pregnant? 30-year-old woman to become pregnant? 40-year-old woman to become pregnant? 3. How likely is it (%) that a pregnant: 20-year-old woman will have a miscarriage? 30-year-old woman will have a miscarriage? 40-year-old woman will have a miscarriage? 4. What percentage of all couple attempting to have children experience infertility? 5. What percentage of couples, in which the woman is over the age of 40, will experience infertility? a b
66.10 (23.34) 57.22 (23.13) 41.62 (23.42)
25b 21–23b 5–8b
3.09 (2.43) 4.69 (3.37) 7.44 (4.60)
5b 6b 7–12
22.39 (14.65) 29.27 (14.11) 44.07 (16.75) 28.73 (13.59)
9–10b 11–12b 29–34b 10–20
53.24 (17.73)
70–90
Correct response according to published literature. p < 0.001.
Bretherick. Fertility and aging knowledge survey. Fertil Steril 2010.
Data Analysis On average, only 0.9% (range ¼ 0.6%–2.2%) of participants failed to select a response for a given knowledge question. These surveys with missing data were excluded from analysis of that question (i.e., means and proportions are composed of only those surveys that indicated a response to the question). All data analysis was conducted using SPSS, Version 16. Data analysis for this study involved [1] descriptive statistics (i.e., means, standard deviations, and proportions); [2] between group comparisons using t tests in which the t value, the P value, and Cohen’s d (29) for effect sizes is reported; and [3] multiple linear regression analysis in which the F statistic and P value are reported in the text. In all cases a P value of .05 or less was considered significant.
RESULTS Knowledge of Reproductive Aging Descriptive data concerning participants’ knowledge of fertility over the life span is presented in Table 1; comparison of participants’ responses regarding likelihood of pregnancy, pregnancy loss, and infertility to published population estimates is presented in Table 2. Participants significantly overestimated the likelihood that a woman at 20, 30, and 40 years of age would become pregnant after 1 month of regular unprotected sex, t (359) ¼ 33.41, P < .001, d ¼ 2.49; t (359) ¼ 28.07, P < .001, d ¼ 2.10; t (359) ¼ 27.24, P < .001, d ¼ 2.03, for 20-, 30-, and 40-year-old women, respectively. Fertility and Sterility
Similarly, participants underestimated the number of months of regular unprotected sex required for the average woman to become pregnant, but only for 20- and 30-year-old women, t (356) ¼ 14.79, P < .001, d ¼ 1.11; t (356) ¼ 7.33, P < .001, d ¼ 0.55, for 20- and 30-year-old women, respectively. Participants’ mean ratings did not differ from population estimates for 40-year-old women, t (355) ¼ 0.06, p¼ .987, d ¼ 0.14. A minority of respondents (15.2%) correctly indicated that a 40-year-old woman has the best chance of becoming pregnant when using the eggs of a 20-year-old donor compared with: her own eggs, eggs donated by a close female relative, or ‘‘in vitro fertilization success does not depend on the origin of the eggs.’’ Women in our sample overestimated the overall risk of infertility, t (357) ¼ 12.15, P < .001, d ¼ 0.91. In contrast, the risk of infertility for a couple in which the woman is over the age of 40 was significantly underestimated, t (357) ¼ 17.88, P <.001, d ¼ 1.34. Most university women (70.3%) correctly identified that fertility drops off significantly well before menopause. However, less than half of our sample (45.5%) correctly identified ‘‘the woman’s age’’ as the strongest risk factor for infertility. Participants in our sample overestimated the risk of pregnancy loss at all ages, t (357) ¼ 16.00, P < .001, d ¼ 1.20; t (356) ¼ 23.13, P < .001, d ¼ 1.73; t (357) ¼ 11.37, P < .001, d ¼ 0.85, for 20-, 30-, and 40year-old women, respectively. However, less than one quarter of our sample (24.7%) correctly identified ‘‘a woman’s age’’ as the strongest risk factor for miscarriage. 2165
TABLE 3 Predictors of intended age at the time of bearing one’s first child. Dependent variable
r2(semipartial)
t
P
.27 .09 .04 .17 .12
4.84 1.54 0.63 3.00 2.11
.000 .124 .527 .003 .04
.06
1.12
.263
Step 1 Participants’ age Marital status Educational aspirations Number of desired children Mothers’ age when she bore her first child Step 2 Knowledge
R2
AdjR2
.13
.11
.13
.12
DR2
.00
Bretherick. Fertility and aging knowledge survey. Fertil Steril 2010.
Childbearing Intentions Most the women in our sample (88.9%) reported a desire to have children. The average number of children desired, among women who reported a desire to have children, was 2.34 (SD ¼ 0.76). Over half (63.7%) of the women who indicated a desire to have children planned to bear their first child between the ages of 25 and 30. The remainder reported the intention to bear their first child before the age of 25 (2.1%), between the ages of 30 and 35 (32.1%), or after 35 (2.1%). Multiple linear regression was used to identify predictors of the age at which participants intend to bear their first child. This analysis was limited to participants who indicated a desire to bear children. The participant’s age, marital status, career plans (how far the participant plans to go in school), number of desired children, and the age at which the participant’s mother bore her first child were entered into step 1 of the regression. Knowledge of fertility over the life span was entered second into the equation. Intended age of bearing one’s first child was the outcome variable. Step 1 of the regression was significant, F(5, 281) ¼ 8.37, P<.001, and predicted 11% of the variance in women’s intended age of bearing their first child. Step 2 of the regression (knowledge of fertility) was not significant, F (1, 280) ¼ 1.26, P¼0.263, indicating that knowledge of fertility and aging was not predictive of a woman’s childbearing intentions. The participant’s age, number of desired children, and the participant’s mother’s age at the time of bearing her first child were found to significantly predict the age at which participants intend to bear their first child. Details of this analysis are presented in Table 3. DISCUSSION Results of this survey suggest that Canadian undergraduate women underestimate the influence of female age on childbearing success. Specifically, although most women were aware that there is a drop in fertility with age, they significantly overestimated the likelihood of pregnancy at all ages, and were unaware of the steep rate at which fertility declines with age. Furthermore, although women in our study overestimated the overall chance of infertility, they underestimated the impact of age on this factor. Interestingly, these women overestimated the chance of pregnancy loss at all 2166
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ages, but failed to identify a woman’s age as the strongest risk factor for this event. University women also demonstrated a general lack of understanding of the influence of a woman’s age on the success of in vitro fertilization. Finally, the following factors emerged as significant predictors of the age at which participants plan to bear their first child: [1] the participant’s age, [2] the number of children that the participant desires, and [3] the age at which the participant’s mother bore her first child. However a woman’s knowledge of fertility and aging was not found to be predictive of her childbearing plans. There are several possible explanations for the general lack of appreciation of the impact of aging on fertility among university women. University health care programs likely have an educational emphasis on pregnancy prevention rather than infertility awareness as this is the more immediate concern of this demographic. Furthermore, university students themselves may not be seeking out information on this topic as it is not yet relevant to them at their current life stage. Media portrayal of pregnancy in women of advanced maternal age is often overly positive. Numerous female celebrities well into their 40s have been depicted on magazine covers with their newborn babies, although information regarding the measures required to achieve motherhood (IVF, donor eggs, surrogate mothers) are rarely discussed. It is likely that a combination of these factors contribute to the knowledge gap in this group. Our findings are consistent with those of similar studies that report that although most women have some awareness of the impact of age on fertility, the magnitude of this effect is significantly underestimated (6, 15, 17, 21, 22, 30). Similar to our findings, in a study of Swedish undergraduates, the probability of a 25- to 30-year-old woman achieving pregnancy was overestimated by 55% of respondents and the probability of a 35- to 40-year-old woman achieving pregnancy was overestimated by 34% (21). Understandably, the proportion of women informed about this issue is higher in certain groups. For example, 85% of new mothers (17) and 80% to 93% of women seeking fertility treatment (6, 19) were aware that female fertility declines with age. The Vol. 93, No. 7, May 1, 2010
general public’s knowledge regarding the incidence of infertility has also been assessed. A random sampling of Canadian women between the ages of 20 and 45 found that although nearly 75% of women knew that the likelihood of conceiving varies with a woman’s age, 41% underestimated the frequency of infertility (15). More than 55% of respondents in a telephone survey of adults across Europe, the United States, and Australia, underestimated the incidence of ‘‘couples that seek medical assistance to overcome an infertility problem’’ by nearly an order of magnitude (30). In contrast, 28% of university undergraduates underestimated the percentage of ‘‘couples that are involuntarily childless’’ whereas 30% of students overestimated this percentage (21). In our dataset there is no significant difference between the mean response in our population and the population mean concerning the incidence of infertility. However, there is a trend toward an overestimation of the incidence of infertility, lending support to the latter study. Discrepancies between studies may be explained by differences in the fertility knowledge of the populations surveyed. Alternatively, participants’ responses may have been influenced by the response scales presented with the question. For example, Adashi et al. (30) used multiple-choice responses of 1/6, 1/10, 1/50, 1/100 or 1/1,000, and Lampic et al. (21) used an open-response format, whereas we presented participants with a 0 to 100% scale in 10% increments. To our knowledge, this study is the first to assess knowledge of the incidence of pregnancy loss and the role of maternal age in this factor. Our finding that age is underestimated as a risk factor for pregnancy loss is not surprising given that women were unaware of the magnitude of the influence of age on fertility in general. This finding adds another dimension to the body of literature demonstrating a lack of knowledge of fertility and aging among reproductive-aged university women. Knowledge of IVF has not been previously assessed with a question similar to that which we posed, which addresses understanding of the maternal-age related factors in IVF success. A study of Swedish graduate students found that 59% of women overestimated the success rate of IVF (22), and a survey of women in the United Kingdom found that 85% of fertility clinic patients and 77% of pregnant women expected IVF to overcome the effects of age (19). Together with our results, this suggests that there is also a lack of knowledge regarding assisted reproductive technology and its ability to compensate for the age-related decline in fertility. The childbearing intentions of respondents in this study are slightly lower than that reported in other surveys of university women. We found that 89% of participants intended to have children, whereas 96% of undergraduate (21) and 91% of graduate (22) students from Sweden report this intention. This may be because of a true difference in desires for children between these different populations. In a random sampling of women aged 20 to 45 from the Canadian province of Alberta, nearly 10% of respondents indicated that they ‘‘never wanted nor never planned to have children’’ (15), sugFertility and Sterility
gesting desire and intent to parent may, in fact, be lower in Canada. Alternatively, differences in childbearing intentions may reflect differences in survey procedures between the two groups. Both Swedish studies used a postal survey of randomly selected of students and surveyed knowledge as well as attitudes and intentions toward parenthood (21, 22), whereas we used volunteer participant ascertainment and surveyed only participant knowledge. Although both methods may have resulted in a bias toward inclusion of women intending to have children, it is conceivable that this bias may have been stronger when women were also surveyed regarding attitudes and intentions towards parenthood, as women not intending parenthood may have felt their responses were not as relevant. Knowledge of fertility over the life span did not emerge as a predictor of intended age of childbearing. Similarly, the intention to have children after the age of 30 was not related to awareness of age-related fertility issues among Swedish female undergraduates (21). There are a number of possible explanations for these findings. This could be because of the fact that in our study women on average possessed fairly low levels of knowledge about the role of age in fertility (i.e., on average participants scored below 50% on fertility and aging knowledge items). It could also be that they are not making use of this information when speculating about the timing of childbearing. Alternatively, university undergraduates may not perceive this information to be relevant to themselves (i.e., ‘‘It won’t happen to me’’). Finally, fertility awareness may be only one of a multitude of factors impacting women’s childbearing intentions, and this study may therefore not have had the power to detect the contribution of this factor. Although financial security, partner suitability, and desire for children were found to be factors influencing decisions about timing of childbearing for >80% of Canadian women, the ‘‘feeling of a biologic clock’’ was an influencing factor for <45% (15). It would therefore be of value to assess the impact of providing fertility awareness information to this age group of women, on childbearing intentions. Furthermore, regardless of the impact of knowledge of fertility on actual or intended age of childbearing, age-related childlessness among women who were aware of the risk of delayed childbearing will likely not be as personally devastating as it is to those who were unaware. Female university students are a population that is likely to delay childbearing, due both to the real and perceived negative effects of parenthood on professional career advancement (5, 7, 16, 31). Although there are undoubtedly many reasons to postpone parenthood, our findings and those of others suggest that there is a lack of knowledge concerning the decrease in fertility with age. The unfortunate result is that many female academics find themselves unintentionally childless, not a product of purposely choosing to remain childless, but rather as a result of the desire to postpone childbearing until their career was established (32). The findings of this survey support the case that there is a need for education on fertility and aging, particularly among this high-risk
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group, and support the growing ‘‘call to action’’ in this area by a number of health care providers in this field (33–35). Our findings are based on a self-selected group of university women, and may therefore not be fully representative of the female university population as a whole. Atlhough the magnitude of this potential bias cannot be assessed, we believe that it likely had a minimal impact as women were recruited at a broad range of campus locations and represent a variety of fields of study. Because surveys were administered over an 11-week period, the distribution of the fact sheet upon survey completion may have resulted in participants having previous knowledge of the correct survey responses. Given this possibility, it is worth keeping in mind that Canadian reproductive age university women may, in fact, possess even less knowledge of the relation between fertility and aging than is reflected in our findings. In addition, our sample is comprised only of university women and may not reflect the knowledge base or views of similarly aged non-university women. Finally, it remains to be demonstrated that knowledge of fertility and aging impacts childbearing plans and subsequent reproductive choices, and has the potential to decrease the rate of unexpected age-related infertility. Future research would benefit from [1] replication of our findings in other locations across Canada and among nonuniversity, reproductive-age women, and [2] intervention studies to assess the impact of increasing knowledge in the area of fertility and aging on future childbearing plans and later reproductive choices.
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12. Djahanbakhch O, Ezzati M, Zosmer A. Reproductive ageing in women. J Pathol 2007;211:219–31. 13. Marcus SF, Brinsden PR. In-vitro fertilization and embryo transfer in women aged 40 years and over. Hum Reprod Update 1996;2:459–68. 14. Luke B, Brown MB. Maternal risk factors for potential maltreatment deaths among healthy singleton and twin infants. Twin Res Hum Genet 2007;10:778–85. 15. Tough S, Benzies K, Fraser-Lee N, Newburn-Cook C. Factors influencing childbearing decisions and knowledge of perinatal risks among Canadian men and women. Matern Child Health J 2007;11:189–98. 16. Hewlett SA. Fast-track women and the quest for children. Fertil Steril 2004;81(Suppl 2):15–8. 17. Tough S, Benzies K, Newburn-Cook C, Tofflemire K, Fraser-Lee N, Faber A, et al. What do women know about the risks of delayed childbearing? Can J Public Health 2006;97:330–4. 18. Ryan GL, Maasen RA, Dokras A, Syrop CH, Van Voorhis BJ. A majority of women delay childbearing in both fertile and infertile groups despite understanding the risks of aging on fertility. Fertil Steril 2005;S73 (American Society of Reproductive Medicine 31st Annual Meeting). 19. Maheshwari A, Porter M, Shetty A, Bhattacharya S. Women’s awareness and perceptions of delay in childbearing. Fertil Steril 2008;90: 1036–42. 20. Hammond KR, Rocconi RP, Steinkampf MP. Perceptions of age and fertility: a survey of reproductive healthcare providers. Fertil Steril 2002;S78 (American Society of Reproductive Medicine 58th Annual Meeting). 21. Lampic C, Svanberg AS, Karlstrom P, Tyden T. Fertility awareness, intentions concerning childbearing, and attitudes towards parenthood among female and male academics. Hum Reprod 2006;21:558–64. 22. Skoog Svanberg A, Lampic C, Karlstrom PO, Tyden T. Attitudes toward parenthood and awareness of fertility among postgraduate students in Sweden. Gend Med 2006;3:187–95. 23. O’Connor KA, Holman DJ, Wood JW. Declining fecundity and ovarian ageing in natural fertility populations. Maturitas 1998;30:127–36. 24. Gindoff PR, Jewelewicz R. Reproductive potential in the older woman. Fertil Steril 1986;46:989–1001. 25. Menken J, Trussell J, Larsen U. Age and infertility. Science 1986;233: 1389–94. 26. van Noord-Zaadstra BM, Looman CW, Alsbach H, Habbema JD, te Velde ER, Karbaat J. Delaying childbearing: effect of age on fecundity and outcome of pregnancy. BMJ 1991;302:1361–5. 27. American Society for Reproductive Medicine. Age and Fertility: A Guide for Patients. Patient information series, 2003. Available at: http://www. asrm.org/Patients/patientbooklets/agefertility.pdf. Last accessed February 18, 2010. 28. Hassan MA, Killick SR. Effect of male age on fertility: evidence for the decline in male fertility with increasing age. Fertil Steril 2003;79(Suppl 3):1520–7. 29. Cohen J. Statistical power analysis for the behavioural sciences. 2nd ed. Mahwah, NJ: Lawrence Erlbaum Associates, 1994. 30. Adashi EY, Cohen J, Hamberger L, Jones HW Jr, de Kretser DM, Lunenfeld B, et al. Public perception on infertility and its treatment: an international survey. The Bertarelli Foundation Scientific Board. Hum Reprod 2000;15:330–4. 31. Gewin V. Baby blues. Nature 2005;433:780–1. 32. Kemkes-Grottenthaler A. Postponing or rejecting parenthood? Results of a survey among female academic professionals. J Biosoc Sci 2003;35: 213–26. 33. Madsen P. Just the facts, ma’am. Coming clean about fertility. Fertil Steril 2003;80(Suppl 4):27–9. 34. Bachrach A. Missed conceptions: a call for ‘‘positive’’ family planning. Med J Aust 2006;184:358–60. 35. Benzies KM. Advanced maternal age: are decisions about the timing of child-bearing a failure to understand the risks? CMAJ 2008;178:183–4.
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Department of Medical Genetics, University of British Columbia, Vancouver; b Interdisciplinary Women’s Reproductive Health Research Training program, Child and Family Research Institute, Vancouver; and c Women’s Health Research Institute, BC Women’s Hospital and Health Centre, Vancouver, British Columbia, Canada
Objective: Female fertility declines with age; however, women are increasingly delaying childbearing until later in their reproductive years. One of the factors that may contribute to this trend is a general lack of knowledge about the decline in fertility with age. Design: Self-report survey. Questions pertained to participant demographics and childbearing intentions, and knowledge of the decline in fertility and increased risk of pregnancy loss with age. Setting: The University of British Columbia in Vancouver, British Columbia, Canada. Patients: Female undergraduate students (N ¼ 360). Intervention(s): None. Main Outcome Measure(s): Knowledge of fertility over the life span, predictors of age of intended childbearing. Result(s): Although most women were aware that fertility declines with age, they significantly overestimated the chance of pregnancy at all ages and were not conscious of the steep rate of fertility decline. Surprisingly, women overestimated the chance of pregnancy loss at all ages, but did not generally identify a woman’s age as the strongest risk factor for miscarriage. Conclusion(s): Education regarding the rate at which reproductive capacity declines with age is necessary to avoid unintended childlessness among female academics and professionals. (Fertil Steril 2010;93:2162–8. 2010 by American Society for Reproductive Medicine.) Key Words: Women, knowledge, fertility, aging, education, survey
In the past few decades there has been a noticeable trend among women in many parts of the developed world to delay childbearing until relatively late into their reproductive years. For example, in the Canadian province of British Columbia, the proportion of first time mothers who are over the age of 30 has increased steadily from <7% in 1968 to 44% in 2005 (1). Moreover, the number of first-time mothers over the age of 35
Received August 13, 2008; revised December 19, 2008; accepted January 7, 2009; published online March 17, 2009. K.L.B. has nothing to declare. N.F. has nothing to declare. L.A. has nothing to declare. S.H.A.H. has nothing to declare. W.P.R. has nothing to declare. The first two authors contributed equally to this work. Supported by a grant from the Interdisciplinary Women’s Reproductive Health Training Program at the Child and Family Research Institute, Vancouver, British Columbia, Canada, awarded to Dr. Karla Bretherick and Dr. Nichole Fairbrother. The present address for Dr. Fairbrother is Genome Sciences Centre, BC Cancer Agency, Vancouver, British Columbia, Canada. This article was presented at the Canadian Fertility and Andrology Society 52nd annual meeting, Ottawa, Ontario, Canada, November 15–18, 2006. Reprint requests: Karla L. Bretherick, Ph.D., BC Cancer Research Centre, 675 West 10th Avenue, Vancouver, BC, V5Z 1L3 Canada (FAX: 604-674-8178; E-mail: [email protected]).
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was nearly 15% in 2005. This trend was first noted >20 years ago (2) and is now prevalent in Canada (3, 4), Europe (5), Australia (6), and the United States (7). What is less publicized, however, is the number of women who fail to achieve a successful pregnancy because of unanticipated problems associated with an age-related decline in fertility. Are young adults today aware of the risks they may be taking when they decide to delay reproduction until they are past their prime fertility? The age-related decline in fertility is attributable to both a decrease in conception rates and an increase in pregnancy loss rates. This decline begins at around age 30 (8), and accelerates after age 35, such that fertility is close to zero by the time a woman reaches age 45 (9). The decline in fertility with age is a result of a reduction in the quantity and quality of oocytes (10–12), which also leads to decreased success in achieving pregnancy by in vitro fertilization (IVF) when using a woman’s own eggs; for a review of this topic, see Marcus and Brinsden (13). In addition, pregnant women at an advanced maternal age also face an increased risk of pregnancy complications such as primary Caesarean delivery, prolonged and dysfunctional labor, pregnancy hypertension, and delivery before 32 weeks (14).
Fertility and Sterility Vol. 93, No. 7, May 1, 2010 Copyright ª2010 American Society for Reproductive Medicine, Published by Elsevier Inc.
0015-0282/10/$36.00 doi:10.1016/j.fertnstert.2009.01.064
Multiple factors, such as waiting for a stable relationship and a desire for professional independence and financial security, have been found to contribute to a woman’s decision to postpone parenthood (3, 5, 6, 15). Female university students in particular, are a group that is likely to delay childbearing in their quest for professional, academic, and career training (5, 7). These women may postpone reproduction because of concerns about the potential negative impact of starting a family on career advancement, and a lack of knowledge concerning the decrease in fertility with age. Indeed, 19% of childless women surveyed at an IVF clinic reported the desire for a career as the reason for having postponed pregnancy, and 18% reported being unaware of the impact of age on fertility (6). Myths about the chances of successful childbearing late in one’s reproductive life, and the social acceptability of delayed parenthood are perpetuated by a media bias in presenting success stories of births to women after age 40, and a lack of discussion about the assisted reproductive technology measures often required to achieve such pregnancies (16). Although knowledge of aging and fertility has been assessed in new mothers (17), women seeking infertility treatments (6, 18, 19), and medical personnel (20), there has been limited study of university women, a population in which this knowledge may be particularly relevant. To our knowledge, three previous studies, all of which were based in Sweden, have assessed knowledge of reproductive aging among university students: [1] a survey of attitudes toward parenting among women attending a university student health center revealed that students understand the association between age and fertility, but overestimate the probability of achieving pregnancy at the time of ovulation, and underestimate age as a factor in infertility (5); [2] a study of undergraduate student’s knowledge of age-related fertility issues found that many students underestimated the effect of age on fertility (21); and [3] a study of female graduate students further supported these findings (22). To date, there has been no assessment of university women in any country other than Sweden regarding knowledge of age-related fertility issues including the impact of aging on likelihood of conception, frequency of infertility, incidence of pregnancy loss, and rate of IVF success. To assess university women’s knowledge of fertility and aging, we developed and administered a survey to female undergraduate students at the University of British Columbia in western Canada. The objective of this project was to illuminate the level of understanding of reproductive aging women in this group possess. In particular, the following hypotheses were proposed: [1] reproductive-aged university women overestimate the chance of pregnancy as they age, [2] reproductive-aged university women underestimate the risk of pregnancy loss as they age, and [3] knowledge of fertility over the life span will predict the age at which female undergraduates intend to bear their first child, over and above the contribution of the woman’s current age, marital status, career plans, field of study, number of desired chilFertility and Sterility
dren, and her mother’s age at the time of first childbearing. To our knowledge, this is the first Canadian survey of university women’s knowledge of fertility and aging. Survey findings highlight the educational needs of this group of women, and can act as the basis for instructive campaigns in this area. METHODS Participants Surveys were administered to 405 female volunteers at the University of British Columbia (UBC) Vancouver campus. To obtain a homogeneous sample and to facilitate understanding of the knowledge and intentions of a specific female population, surveys in which the volunteer was not enrolled in a UBC undergraduate program (n ¼ 45) were excluded before data analysis. Excluded surveys included those completed by graduate and professional students (n ¼ 33), visiting students (n ¼ 3), university staff (n ¼ 3), and those for which student status was not reported (n ¼ 6). The remaining surveys (89%) were completed by 360 female undergraduate students representing approximately 2% of the total female undergraduate students enrolled at this campus. Participants ranged in age from 18 to 42, with a mean age of 21.28 years (SD ¼ 2.81), reflecting the UBC population in which 74% of undergraduate students are between 18 and 24 years of age. Most participants were single (88.8%), and Caucasian (52.0%) or Asian (29.9%). Participants’ primary fields of study represent a broad range of disciplines, including arts (24.4%), social sciences (23.2%), health sciences (21.8%), basic sciences (19.1%), applied sciences (3.6%), business (3.4%), agricultural sciences (2.5%), education (0.8%), and others (1.1%). Most participants reported being in their first 4 years of undergraduate study (90.6%) with a small number being in their fifth year of study (9.4%). Measures The Reproductive Health Survey was developed for the purposes of this research and contained questions pertaining to the following: demographic information (5 items), family information and childbearing intentions (4 items), fertility and infertility (10 items), pregnancy loss (4 items), and assisted reproductive technologies (1 item). A multiple-choice response format was used for most the survey questions. For questions regarding knowledge of the likelihood of an event, a scale of from 0 to 100% in 10% increments was presented, and participants were asked to circle their response. For questions regarding time required for an event, a scale of 0 to 20 in 2-month increments was presented. A small number of the demographic and family background questions used an open-ended response format (e.g., race/ethnicity, mother’s age when she bore her first child). The survey required approximately 20 minutes of the participant’s time to complete. Survey questions were compiled collaboratively by the investigators, representing the fields of psychology (survey development) and medical genetics (fertility and aging). Feedback from other investigators who are knowledgeable in the area of 2163
TABLE 1 Descriptive data concerning fertility over the life span. Survey item
%
1. Which of the following is the strongest risk factor for infertility? The woman’s agea Physical or emotional stress Exposure to cigarette smoke Long term use of the birth control pill 2. Which of the following scenarios most accurately describes a woman’s fertility over her lifetime? Fertility significantly drops off more than a decade prior to menopausea Fertility stays about the same from the onset of menstruation until menopause Fertility increases with age from the onset of menstruation until menopause Women remain fertile even several years after menopause 3. Which is the strongest risk factor for miscarriage? Physical or emotional stress The woman’s agea Exposure to cigarette smoke Strenuous exercise during pregnancy Long-term use of the birth control pill 4. A 40-year-old woman undergoing in vitro fertilization has the best chance of becoming pregnant when using: In vitro fertilization success does not depend on origin of eggs Her own eggs Eggs donated by a 20-year-old donora Eggs donated by a close female relative a
46.0 25.9 19.0 9.2
70.3 20.1
6.5
3.1
47.7 24.7 14.5 9.7 3.4
43.1 36.3 15.2 5.4
Correct response according to published literature.
Bretherick. Fertility and aging knowledge survey. Fertil Steril 2010.
survey development and life span fertility was sought and used to modify the initial version. Following this initial development, the survey was piloted with a small number of reproductive-aged university women and modified to incorporate their feedback. The final version of the survey was administered to participants. Correct responses for multiple choice questions were compiled from a number of sources (23–27) and are indicated by bold lettering in Table 1. For responses in Table 2, we com2164
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pared the sample mean response with the known population mean using one-sample t tests. Population means described in the literature (24, 26–28) are not entirely concordant with one another, but span a narrow range of values. To reduce the likelihood of incorrectly assigning significance where in fact no difference exists (type 1 error), the population value on the end of the range that differed least from the sample mean was used for each statistical analysis. To test the hypothesis that knowledge of fertility over the life span will predict the age at which reproductive aged women intend to bear their first child, we created a composite knowledge of fertility over the life span score based on responses to items 1 and 2 on Table 1, and items 1 and 2 on Table 2. In addition, participants were also given two trend scores based on items 1 (i.e., ‘‘What is the chance that a 20-, 30-, and 40-year-old woman will become pregnant after 1 month of regular unprotected sex?’’), and 2 (‘‘How many months does it take for the average 20-, 30-, and 40year-old woman to become pregnant if she is having regular unprotected sex?’’) in Table 2. This means that even if a woman underestimated or overestimated the effect of aging on the probability of achieving pregnancy, if she appreciated the direction of this effect (i.e., that the chances of achieving pregnancy decline as one ages), she was given a point for this. Responses to the eight survey questions and the two trends were scored on a 0 to 1 scale, with 0 for a fully incorrect response and 1 for a fully correct response. A score of 0.5 was given in instances where a partially correct response was given. This scoring system resulted in a knowledge score with a possible range of 0 to 10. Scores on the composite knowledge scale spanned the full range of possible scores (i.e., from 1 to 10) with a mean of 4.13 (i.e., 41% correct), and a standard deviation of 2.09. Procedures Participants were recruited in public locations across the Vancouver campus of the UBC between February 2, 2006 and April 19, 2006. Participants who voluntarily responded to a poster advertisement at the survey table completed the Reproductive Health Survey and the project consent form under the supervision of a survey administrator. As volunteers were self-selected, we are unable to determine the response rate of the target sample. Participants returned the survey and were given a small food item and a fact sheet pertaining to fertility and aging in appreciation for their time and effort. Fact sheets included information on the decline in monthly chance of pregnancy with age, the average age and decline in fertility preceding menopause, the incidence of infertility and miscarriage according to age, and the success rates of in vitro fertilization at various ages. Surveys were filled out anonymously and confidentially, identified only by date of administration and birth date, and assigned a survey number upon entry of data into the project database. Approval for the project was obtained from the Behavioral Research Ethics Board of the UBC (approval number B05-0832). The investigators declare no conflict of interest in this research. Vol. 93, No. 7, May 1, 2010
TABLE 2 Comparison of mean participant responses to population estimates. Participant Population response mean (SD) meana
Survey item 1. What is the chance (%) that after 1 month of regular unprotected sex a: 20-year-old woman will become pregnant? 30-year-old woman will become pregnant? 40-year-old woman will become pregnant? 2. How many months of regular unprotected sex does it take for the average: 20-year-old woman to become pregnant? 30-year-old woman to become pregnant? 40-year-old woman to become pregnant? 3. How likely is it (%) that a pregnant: 20-year-old woman will have a miscarriage? 30-year-old woman will have a miscarriage? 40-year-old woman will have a miscarriage? 4. What percentage of all couple attempting to have children experience infertility? 5. What percentage of couples, in which the woman is over the age of 40, will experience infertility? a b
66.10 (23.34) 57.22 (23.13) 41.62 (23.42)
25b 21–23b 5–8b
3.09 (2.43) 4.69 (3.37) 7.44 (4.60)
5b 6b 7–12
22.39 (14.65) 29.27 (14.11) 44.07 (16.75) 28.73 (13.59)
9–10b 11–12b 29–34b 10–20
53.24 (17.73)
70–90
Correct response according to published literature. p < 0.001.
Bretherick. Fertility and aging knowledge survey. Fertil Steril 2010.
Data Analysis On average, only 0.9% (range ¼ 0.6%–2.2%) of participants failed to select a response for a given knowledge question. These surveys with missing data were excluded from analysis of that question (i.e., means and proportions are composed of only those surveys that indicated a response to the question). All data analysis was conducted using SPSS, Version 16. Data analysis for this study involved [1] descriptive statistics (i.e., means, standard deviations, and proportions); [2] between group comparisons using t tests in which the t value, the P value, and Cohen’s d (29) for effect sizes is reported; and [3] multiple linear regression analysis in which the F statistic and P value are reported in the text. In all cases a P value of .05 or less was considered significant.
RESULTS Knowledge of Reproductive Aging Descriptive data concerning participants’ knowledge of fertility over the life span is presented in Table 1; comparison of participants’ responses regarding likelihood of pregnancy, pregnancy loss, and infertility to published population estimates is presented in Table 2. Participants significantly overestimated the likelihood that a woman at 20, 30, and 40 years of age would become pregnant after 1 month of regular unprotected sex, t (359) ¼ 33.41, P < .001, d ¼ 2.49; t (359) ¼ 28.07, P < .001, d ¼ 2.10; t (359) ¼ 27.24, P < .001, d ¼ 2.03, for 20-, 30-, and 40-year-old women, respectively. Fertility and Sterility
Similarly, participants underestimated the number of months of regular unprotected sex required for the average woman to become pregnant, but only for 20- and 30-year-old women, t (356) ¼ 14.79, P < .001, d ¼ 1.11; t (356) ¼ 7.33, P < .001, d ¼ 0.55, for 20- and 30-year-old women, respectively. Participants’ mean ratings did not differ from population estimates for 40-year-old women, t (355) ¼ 0.06, p¼ .987, d ¼ 0.14. A minority of respondents (15.2%) correctly indicated that a 40-year-old woman has the best chance of becoming pregnant when using the eggs of a 20-year-old donor compared with: her own eggs, eggs donated by a close female relative, or ‘‘in vitro fertilization success does not depend on the origin of the eggs.’’ Women in our sample overestimated the overall risk of infertility, t (357) ¼ 12.15, P < .001, d ¼ 0.91. In contrast, the risk of infertility for a couple in which the woman is over the age of 40 was significantly underestimated, t (357) ¼ 17.88, P <.001, d ¼ 1.34. Most university women (70.3%) correctly identified that fertility drops off significantly well before menopause. However, less than half of our sample (45.5%) correctly identified ‘‘the woman’s age’’ as the strongest risk factor for infertility. Participants in our sample overestimated the risk of pregnancy loss at all ages, t (357) ¼ 16.00, P < .001, d ¼ 1.20; t (356) ¼ 23.13, P < .001, d ¼ 1.73; t (357) ¼ 11.37, P < .001, d ¼ 0.85, for 20-, 30-, and 40year-old women, respectively. However, less than one quarter of our sample (24.7%) correctly identified ‘‘a woman’s age’’ as the strongest risk factor for miscarriage. 2165
TABLE 3 Predictors of intended age at the time of bearing one’s first child. Dependent variable
r2(semipartial)
t
P
.27 .09 .04 .17 .12
4.84 1.54 0.63 3.00 2.11
.000 .124 .527 .003 .04
.06
1.12
.263
Step 1 Participants’ age Marital status Educational aspirations Number of desired children Mothers’ age when she bore her first child Step 2 Knowledge
R2
AdjR2
.13
.11
.13
.12
DR2
.00
Bretherick. Fertility and aging knowledge survey. Fertil Steril 2010.
Childbearing Intentions Most the women in our sample (88.9%) reported a desire to have children. The average number of children desired, among women who reported a desire to have children, was 2.34 (SD ¼ 0.76). Over half (63.7%) of the women who indicated a desire to have children planned to bear their first child between the ages of 25 and 30. The remainder reported the intention to bear their first child before the age of 25 (2.1%), between the ages of 30 and 35 (32.1%), or after 35 (2.1%). Multiple linear regression was used to identify predictors of the age at which participants intend to bear their first child. This analysis was limited to participants who indicated a desire to bear children. The participant’s age, marital status, career plans (how far the participant plans to go in school), number of desired children, and the age at which the participant’s mother bore her first child were entered into step 1 of the regression. Knowledge of fertility over the life span was entered second into the equation. Intended age of bearing one’s first child was the outcome variable. Step 1 of the regression was significant, F(5, 281) ¼ 8.37, P<.001, and predicted 11% of the variance in women’s intended age of bearing their first child. Step 2 of the regression (knowledge of fertility) was not significant, F (1, 280) ¼ 1.26, P¼0.263, indicating that knowledge of fertility and aging was not predictive of a woman’s childbearing intentions. The participant’s age, number of desired children, and the participant’s mother’s age at the time of bearing her first child were found to significantly predict the age at which participants intend to bear their first child. Details of this analysis are presented in Table 3. DISCUSSION Results of this survey suggest that Canadian undergraduate women underestimate the influence of female age on childbearing success. Specifically, although most women were aware that there is a drop in fertility with age, they significantly overestimated the likelihood of pregnancy at all ages, and were unaware of the steep rate at which fertility declines with age. Furthermore, although women in our study overestimated the overall chance of infertility, they underestimated the impact of age on this factor. Interestingly, these women overestimated the chance of pregnancy loss at all 2166
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ages, but failed to identify a woman’s age as the strongest risk factor for this event. University women also demonstrated a general lack of understanding of the influence of a woman’s age on the success of in vitro fertilization. Finally, the following factors emerged as significant predictors of the age at which participants plan to bear their first child: [1] the participant’s age, [2] the number of children that the participant desires, and [3] the age at which the participant’s mother bore her first child. However a woman’s knowledge of fertility and aging was not found to be predictive of her childbearing plans. There are several possible explanations for the general lack of appreciation of the impact of aging on fertility among university women. University health care programs likely have an educational emphasis on pregnancy prevention rather than infertility awareness as this is the more immediate concern of this demographic. Furthermore, university students themselves may not be seeking out information on this topic as it is not yet relevant to them at their current life stage. Media portrayal of pregnancy in women of advanced maternal age is often overly positive. Numerous female celebrities well into their 40s have been depicted on magazine covers with their newborn babies, although information regarding the measures required to achieve motherhood (IVF, donor eggs, surrogate mothers) are rarely discussed. It is likely that a combination of these factors contribute to the knowledge gap in this group. Our findings are consistent with those of similar studies that report that although most women have some awareness of the impact of age on fertility, the magnitude of this effect is significantly underestimated (6, 15, 17, 21, 22, 30). Similar to our findings, in a study of Swedish undergraduates, the probability of a 25- to 30-year-old woman achieving pregnancy was overestimated by 55% of respondents and the probability of a 35- to 40-year-old woman achieving pregnancy was overestimated by 34% (21). Understandably, the proportion of women informed about this issue is higher in certain groups. For example, 85% of new mothers (17) and 80% to 93% of women seeking fertility treatment (6, 19) were aware that female fertility declines with age. The Vol. 93, No. 7, May 1, 2010
general public’s knowledge regarding the incidence of infertility has also been assessed. A random sampling of Canadian women between the ages of 20 and 45 found that although nearly 75% of women knew that the likelihood of conceiving varies with a woman’s age, 41% underestimated the frequency of infertility (15). More than 55% of respondents in a telephone survey of adults across Europe, the United States, and Australia, underestimated the incidence of ‘‘couples that seek medical assistance to overcome an infertility problem’’ by nearly an order of magnitude (30). In contrast, 28% of university undergraduates underestimated the percentage of ‘‘couples that are involuntarily childless’’ whereas 30% of students overestimated this percentage (21). In our dataset there is no significant difference between the mean response in our population and the population mean concerning the incidence of infertility. However, there is a trend toward an overestimation of the incidence of infertility, lending support to the latter study. Discrepancies between studies may be explained by differences in the fertility knowledge of the populations surveyed. Alternatively, participants’ responses may have been influenced by the response scales presented with the question. For example, Adashi et al. (30) used multiple-choice responses of 1/6, 1/10, 1/50, 1/100 or 1/1,000, and Lampic et al. (21) used an open-response format, whereas we presented participants with a 0 to 100% scale in 10% increments. To our knowledge, this study is the first to assess knowledge of the incidence of pregnancy loss and the role of maternal age in this factor. Our finding that age is underestimated as a risk factor for pregnancy loss is not surprising given that women were unaware of the magnitude of the influence of age on fertility in general. This finding adds another dimension to the body of literature demonstrating a lack of knowledge of fertility and aging among reproductive-aged university women. Knowledge of IVF has not been previously assessed with a question similar to that which we posed, which addresses understanding of the maternal-age related factors in IVF success. A study of Swedish graduate students found that 59% of women overestimated the success rate of IVF (22), and a survey of women in the United Kingdom found that 85% of fertility clinic patients and 77% of pregnant women expected IVF to overcome the effects of age (19). Together with our results, this suggests that there is also a lack of knowledge regarding assisted reproductive technology and its ability to compensate for the age-related decline in fertility. The childbearing intentions of respondents in this study are slightly lower than that reported in other surveys of university women. We found that 89% of participants intended to have children, whereas 96% of undergraduate (21) and 91% of graduate (22) students from Sweden report this intention. This may be because of a true difference in desires for children between these different populations. In a random sampling of women aged 20 to 45 from the Canadian province of Alberta, nearly 10% of respondents indicated that they ‘‘never wanted nor never planned to have children’’ (15), sugFertility and Sterility
gesting desire and intent to parent may, in fact, be lower in Canada. Alternatively, differences in childbearing intentions may reflect differences in survey procedures between the two groups. Both Swedish studies used a postal survey of randomly selected of students and surveyed knowledge as well as attitudes and intentions toward parenthood (21, 22), whereas we used volunteer participant ascertainment and surveyed only participant knowledge. Although both methods may have resulted in a bias toward inclusion of women intending to have children, it is conceivable that this bias may have been stronger when women were also surveyed regarding attitudes and intentions towards parenthood, as women not intending parenthood may have felt their responses were not as relevant. Knowledge of fertility over the life span did not emerge as a predictor of intended age of childbearing. Similarly, the intention to have children after the age of 30 was not related to awareness of age-related fertility issues among Swedish female undergraduates (21). There are a number of possible explanations for these findings. This could be because of the fact that in our study women on average possessed fairly low levels of knowledge about the role of age in fertility (i.e., on average participants scored below 50% on fertility and aging knowledge items). It could also be that they are not making use of this information when speculating about the timing of childbearing. Alternatively, university undergraduates may not perceive this information to be relevant to themselves (i.e., ‘‘It won’t happen to me’’). Finally, fertility awareness may be only one of a multitude of factors impacting women’s childbearing intentions, and this study may therefore not have had the power to detect the contribution of this factor. Although financial security, partner suitability, and desire for children were found to be factors influencing decisions about timing of childbearing for >80% of Canadian women, the ‘‘feeling of a biologic clock’’ was an influencing factor for <45% (15). It would therefore be of value to assess the impact of providing fertility awareness information to this age group of women, on childbearing intentions. Furthermore, regardless of the impact of knowledge of fertility on actual or intended age of childbearing, age-related childlessness among women who were aware of the risk of delayed childbearing will likely not be as personally devastating as it is to those who were unaware. Female university students are a population that is likely to delay childbearing, due both to the real and perceived negative effects of parenthood on professional career advancement (5, 7, 16, 31). Although there are undoubtedly many reasons to postpone parenthood, our findings and those of others suggest that there is a lack of knowledge concerning the decrease in fertility with age. The unfortunate result is that many female academics find themselves unintentionally childless, not a product of purposely choosing to remain childless, but rather as a result of the desire to postpone childbearing until their career was established (32). The findings of this survey support the case that there is a need for education on fertility and aging, particularly among this high-risk
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group, and support the growing ‘‘call to action’’ in this area by a number of health care providers in this field (33–35). Our findings are based on a self-selected group of university women, and may therefore not be fully representative of the female university population as a whole. Atlhough the magnitude of this potential bias cannot be assessed, we believe that it likely had a minimal impact as women were recruited at a broad range of campus locations and represent a variety of fields of study. Because surveys were administered over an 11-week period, the distribution of the fact sheet upon survey completion may have resulted in participants having previous knowledge of the correct survey responses. Given this possibility, it is worth keeping in mind that Canadian reproductive age university women may, in fact, possess even less knowledge of the relation between fertility and aging than is reflected in our findings. In addition, our sample is comprised only of university women and may not reflect the knowledge base or views of similarly aged non-university women. Finally, it remains to be demonstrated that knowledge of fertility and aging impacts childbearing plans and subsequent reproductive choices, and has the potential to decrease the rate of unexpected age-related infertility. Future research would benefit from [1] replication of our findings in other locations across Canada and among nonuniversity, reproductive-age women, and [2] intervention studies to assess the impact of increasing knowledge in the area of fertility and aging on future childbearing plans and later reproductive choices.
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