- Email: [email protected]
Effects of prenatal maternal mental distress on birth outcomes
G Model
WOMBI-520; No. of Pages 5 Women and Birth xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Women and Birth journal homepage: www.elsevier.com/locate/wombi
ORIGINAL RESEARCH – QUANTITATIVE
Effects of prenatal maternal mental distress on birth outcomes Shwu-Ru Liou a, Panchalli Wang b, Ching-Yu Cheng a,* a b
College of Nursing, Chang Gung University of Science and Technology, Chiayi Campus, Taiwan Department of Obstetrics and Gynecology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Taiwan
A R T I C L E I N F O
Article history: Received 9 October 2015 Received in revised form 18 February 2016 Accepted 29 March 2016 Keywords: Stress Anxiety Depression Premature birth Low birth weight
A B S T R A C T
Background: Adverse effects of maternal mental distress during pregnancy have been extensively investigated, but the impact of prenatal maternal mental distress at various time periods during pregnancy on birth outcomes is rarely discussed. By understanding the relationship between maternal mental distress and unfavourable birth outcomes throughout pregnancy, appropriate evidence-based preventative care or intervention may be adopted in a timely manner. Aim: This study intended to investigate the effects of maternal stress, anxiety, and depressive symptoms across pregnancy on preterm birth and low birth weight. Methods: With a prospective longitudinal design, this study used the 10-item Perceived Stress Scale, Center for Epidemiologic Studies Depression Scale, and Zung Self-reported Anxiety Scale to investigate 197 participants who, at greater than 24 gestational weeks, completed the self-administered questionnaires during regular checkups in a hospital in southern Taiwan. Descriptive statistics, Mann–Whitney U test/Kruskal–Wallis test, and hierarchical logistic regression were applied for data analysis. Findings: The study found that anxiety and depressive symptoms at 25–29 gestational weeks could predict preterm birth, and that anxiety at greater than 30 gestational weeks was able to predict low birthweight. However, stress was not able to predict any kind of negative birth outcomes. Conclusion: Adverse birth outcomes were somewhat predictable by maternal mental distress; therefore, we suggested that prenatal visits incorporate psychological assessment for early detection and management to prevent possible adverse birth outcomes. ß 2016 Australian College of Midwives. Published by Elsevier Australia (a division of Reed International Books Australia Pty Ltd). All rights reserved.
Summary of relevance: Problem
What this paper adds
The impact of prenatal maternal mental distress at various time periods during pregnancy on birth outcomes is rarely discussed.
Anxiety and depressive symptoms at 25–29 gestational weeks could predict preterm birth whereas anxiety at greater than 30 gestational weeks was able to predict infant low birth weight.
What is already known Certain prenatal negative psychosocial emotions may activate the hypothalamic–pituitary–adrenal (HPA) axis and further suppress the immune system of a pregnant woman; the chronicity and/or excessive activation of the HPA axis can lead to adverse health outcomes.
* Corresponding author at: College of Nursing, Chang Gung University of Science and Technology, No. 2, Chiapu Rd. West Sec., Putz City, Chiayi 613, Taiwan. Tel.: +886 5 362 8800x2603; fax: +886 5 362 8866. E-mail address: [email protected] (C.-Y. Cheng).
1. Introduction Certain psychological distress experienced by women during pregnancy may cause adverse effects on birth outcomes. Among various adverse birth outcomes, preterm birth and low birth weight have gained extensive attention. Preterm birth is a significant cause of neonatal morbidity and mortality.1 Most premature babies are born underweight, and those with very low birth weight often face medical conditions and are likely to have growth and development issues.2,3 In 2010, the estimated
http://dx.doi.org/10.1016/j.wombi.2016.03.004 1871-5192/ß 2016 Australian College of Midwives. Published by Elsevier Australia (a division of Reed International Books Australia Pty Ltd). All rights reserved.
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 2
S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
average preterm birth rate in 184 countries, excluding Taiwan, was 11.1%.4 Although premature birth rate (9.05%) in 2013 in Taiwan was lower compared to the global average figure, more than half of those premature infants (56.33%) were born with low birth weight.5 Due to the high costs of hospitalisation and treatment for premature birth or low birth weight,6 health researchers and professionals have tried to understand the causes and related factors of these two unfavourable birth outcomes. From a physiological point of view, certain prenatal maternal psychosocial factors such as stress and other negative emotions may activate the hypothalamic–pituitary–adrenal (HPA) axis and further suppress the immune system of a pregnant woman; the chronicity and/or excessive activation of the HPA axis can lead to adverse health outcomes, including preterm birth and low birth weight.7 Based on this aspect, many researchers devoted themselves to confirming the relationship between maternal mental distress (e.g. stress, anxiety, and depression) and negative birth outcomes (e.g. premature birth and low birth weight). However, the evidence linking maternal mental distress to adverse birth outcomes is inconclusive. While some studies have confirmed that stress, depression, or anxiety is related to prematurity or low birth weight, other studies yielded very small or non-significant evidence.8–11 Although the correlation has not yet been confirmed, adverse effects of maternal mental distress during pregnancy have been vastly investigated; yet the impact of prenatal maternal mental distress on birth outcomes at various time periods during pregnancy is rarely discussed. By understanding the relationship between maternal mental distress and unfavourable birth outcomes throughout pregnancy, proper preventative care or treatment intervention might be adopted at the right time for the right person. Therefore, we conducted this research to understand (a) whether adverse birth outcomes (i.e. preterm birth or low birth weight) can be predicted by prenatal maternal mental distress (i.e. stress, anxiety, or depressive symptoms), and (b) at what time during pregnancy can prenatal maternal mental distress predict adverse birth outcomes? In this present study, preterm birth was defined as births before 37 weeks of gestation and low birth weight was defined as weight at birth less than 2500 g.
2. Participants, ethics and methods 2.1. Pilot study A pilot test was first conducted to help determine proper sample size for the main study. The pilot study was a crosssectional study design. One-hundred thirty women who were pregnant over 24 gestational weeks were recruited to complete a set of questionnaires measuring anxiety, depressive symptoms, and stress. We found in the pilot study that the correlation coefficient between stress, depressive symptoms, and anxiety was between 0.45 and 0.66. Using the G*Power analysis program with critical value of 0.05 and two-tailed test, 47 and 16 participants respectively were needed to achieve a power of 90%. 2.2. Main study 2.2.1. Design This study used a prospective longitudinal design to explore the impact of prenatal maternal mental distress on birth outcomes. The participants were recruited when they were over 24 gestational weeks and were followed up monthly, finishing with a total of three survey times (T1: 25–29 gestational weeks, T2: 30–34 gestational weeks, T3: >34 gestational weeks).
2.2.2. Sampling Pregnant women who were 18 years of age or older, able to read and write Chinese, over 24 gestational weeks, singleton, and who did not have any pregnancy complications (including diagnosed psychological disorders) were invited to participate in the study. Based on the sample size estimated using the results of the pilot study and a high attrition rate anticipated due to the longitudinal design of this present study,12 we invited as many participants as possible during the study period between February 2010 and October 2011. In the beginning, 264 pregnant women were approached and 56 declined to participate. With 11 dropouts after the second survey, 197 participants completed the entire study (response rate = 74.62%). One participant did not complete the T2 survey and three did not complete the T3 survey due to preterm birth; therefore, there were 197, 196, and 194 valid questionnaires at T1, T2 and T3, respectively. There were no statistically significant differences in the demographic variables between those women that dropped out of the study and participants that were retained. 2.2.3. Instruments Three instruments were used to assess the participants’ levels of stress, depressive symptoms and anxiety. 2.2.3.1. Perceived stress. We used the 10-item Perceived Stress Scale (PSS-10) to measure the degree by which situations were appraised as stressful in one’s life.13 It is a 10-item, five-point scale, ranging from 0 to 4. A higher score on the PSS-10 indicates a higher level of perceived stress. The scale has been translated into Chinese and used among Chinese new mothers,14,15 and the reliability of the Chinese version was satisfactory (Cronbach’s alpha = 0.87). The Cronbach’s alpha of the PSS-10 in this study was 0.87. 2.2.3.2. Depressive symptoms. Developed by Radloff, the Center for Epidemiologic Studies Depression Scale (CES-D), a 20-item, fourpoint (scores 0–3) response, self-reported scale was used to measure the participants’ level of depressive symptoms. The higher the score, the greater the severity of depressive symptoms experienced.14 In Radloff’s original work, the cutoff point for depression was 16, with the Cronbach’s alphas ranging from 0.84 to 0.90, and the 2, 4, 6, and 8 weeks of test–retest correlations ranging from 0.51 to 0.67.14 The CES-D has been used in Chinese new mothers with satisfactory Cronbach’s alphas.15,16 The Cronbach’s alpha of the CES-D in this study was 0.89. 2.2.3.3. Perceived anxiety. Developed to evaluate the presence ofanxiety, the Zung Self-reported Anxiety Scale (SAS) is a 20-item, four-point (scores 1–4) scale.17 A higher score indicates a higher perceived level of anxiety. The SAS has been validated among Vietnamese women during perinatal period (Cronbach’s alpha = 0.76)18 and among Chinese women with a history of spontaneous abortion or induced abortion during a subsequent pregnancy with a satisfactory internal consistency (Cronbach’s alpha = 0.81).19 The reliability of the SAS in this study was tested using the data gathered at the first time period (25–29 gestational weeks). Results showed that the Cronbach’s alpha of the whole scale was 0.65, and two items (‘‘I can breathe in and out easily’’ and ‘‘I fall asleep easily and get a good night’s rest’’) had negative, low itemtotal correlation coefficients (r = 0.02 and 0.14, respectively). By deleting these two items, the Cronbach’s alpha increased to 0.72, and factor analysis showed that the remaining 18 items could explain 53.39% of the variance of anxiety. The 18-item SAS was therefore used in the study for subsequent data collections. 2.2.4. Procedure Before the study commenced, an approval of the study protocol from the Institutional Review Board was obtained by the
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
3
The prevalence rate of depressive symptoms experienced by the participants at T1, T2, and T3 was 25.9%, 25.5%, and 24.2% respectively, which indicated that around 25% of the participants experienced depressive symptoms during pregnancy. This present study can only generate point prevalence of depressive symptoms because the other two screening tools did not have a cutoff point. However, as shown in Table 1, the levels of anxiety and stress perceived by the participants were low, since all item mean scores of the PSS and SAS were below average.
participating hospital. Participants were recruited via professional referrals and personal contacts in a teaching hospital in southern Taiwan. A trained research assistant approached pregnant women who were about to receive prenatal checkups in the waiting area, and provided sufficient information including the purpose of the study and research subjects’ rights to those women. After signing the informed consent, all participants were asked to complete a set of paper questionnaires monthly; they could either complete the questionnaires in the outpatient waiting area or bring the questionnaires home to complete and return via addressed, postage paid envelopes. The questionnaires were kept confidential and contained a random-assigned number that could trace the participant by the researcher. Appointments for data collection were made in accordance with the dates of the participants’ prenatal checkups.
3.2. Comparing differences in measured variables by demographic groups Among the demographic variables, only age and parity were related to gestational weeks at birth; older women and multiparas were likely to give birth at earlier gestation with or without preterm than their counterparts. In contrast, none of the demographic variables were related to birth weight. The analysis of differences in measured variables by demographic groups is shown in Table 2.
2.3. Data analysis Collected data were managed and analysed using SPSS version 18.0. All data were examined for missing values and normality before inferential statistical analysis was conducted. Results showed that there was only one missing value on T3 PSS and the missing value was managed by using expectation–maximisation (EM) algorithm. All measured variables at all collecting time points were not normally distributed (Shapiro–Wilk statistics ranged 0.90–0.99, p ranged <0.001–0.04). Therefore, nonparametric statistical analyses were used. Descriptive statistics were used to understand the participants’ demographic information and levels of measured variables. The Mann–Whitney U test and Kruskal–Wallis test were used to compare differences in measured variables by demographic groups. Hierarchical logistic regression was used to test the predictive power of measured variables for preterm birth and low birth weight. In the logistic regression analysis, demographic variables that were related to preterm birth or low birth weight were entered in the first set, T1 measured variables were in the second set, T2 measured variables were in the third set, and T3 measured variables were in the fourth set.
3.3. Logistic regression analysis Table 3 illustrates the predictive ability of measured variables on birth outcomes. Parity, age, T1 depressive symptoms, and T1 anxiety could predict preterm birth, while T2 and T3 anxiety were able to predict low birth weight. Stress had no predictive power on either preterm birth or low birth weight.
4. Discussion From the results, it seemed that different maternal distress at different prenatal periods had various influences on birth outcomes: stress throughout pregnancy could not predict any forms of birth outcome, anxiety and depressive symptoms at T1 could predict premature birth, and anxiety at T2 and T3 could predict low birth weight. Contrary to expectations, we did not find that stress perceived by pregnant women at more than 24 weeks of gestation had any effect on either preterm birth or low birth weight. A previous research conducted by Roy-Matton et al. found that women with preterm birth perceived higher levels of stress before 20 gestational weeks than those with term pregnancy, but the perception was dismissed after 25 weeks.20 Although some researchers found a relationship between perceived stress and preterm birth, they did not specify what gestational stage was influential.21 Based on both the results yielded from Roy-Matton et al.20 and this present study, the impact of stress on preterm birth seems not to be significant at and after 25 weeks of pregnancy. We found that maternal anxiety at 25–29 gestational weeks had an impact on preterm birth. Amiri et al. also found that prenatal anxiety (20–28 weeks) was related to preterm birth22; however, Dayan et al. found no association between preterm birth and anxiety at the same time period (20–28 weeks).23 In addition, our finding that maternal anxiety at greater than 30 weeks was not able to predict preterm birth was consistent with a previous study,
3. Results 3.1. Descriptive statistics The mean age of the participants was 29.71 (SD = 4.42, range 19–42) years, and the mean gestational age during the first data collection time was 27.34 (SD = 1.08, range 25–29) weeks. The majority of the participants were primipara (56.3%). Almost all of the participants were married or cohabited (99.0%), and about half of them planned the index pregnancy (51.3%). About two thirds of the participants had an educational level of college or higher (68%), and most of the participants were employed (59.9%). Most participants gave birth vaginally (72.6%). The mean birth weight of the newborns was 3028.12 (SD = 341.43, range 1820–3940) g, and the mean gestational age at birth was 38.20 (SD = 1.37, range 32–41) weeks. Nineteen babies (9.6%) were born prematurely (<37 weeks), and 11 babies (5.6%) had a low birth weight (<2500 g). Table 1 Sample means of measured variables across different time periods. T2
T1
Stress Depressive symptoms Anxiety
T3
Scale M SD
Item M SD
Scale M SD
Item M SD
Scale M SD
Item M SD
17.17 5.21 11.16 8.32 41.28 7.53
1.72 0.52 0.56 0.42 2.06 0.38
16.46 5.18 11.53 8.04 43.69 6.75
1.65 0.52 0.58 0.40 2.18 0.34
16.30 5.16 11.16 7.89 43.62 7.51
1.63 0.52 0.56 0.39 2.18 0.38
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
4
Table 2 Comparison of gestational age at birth and birth weight by demographic variables. Gestational age at birth (weeks) M SD Parity Primipara Multipara Employment Employed Unemployed Education Less than college College or higher Planned pregnancy No Yes
Birth weight (g)
t
p
14.06
<0.001
M SD
38.68 1.10 37.59 1.45
p
1.89
0.22
0.99
1.00
0.10
0.75
1.04
0.36
3017.16 305.95 3042.26 383.82 0.001
1.00
38.16 1.37 38.28 1.38
3021.86 358.18 3038.97 312.36 0.002
1.00
38.22 1.43 38.19 1.35
3046.13 336.40 3019.65 344.70 0.02
1.00
38.29 1.52 38.12 1.21
3024.52 357.49 3031.53 327.20
Gestational age at birth (weeks)
Birth weight (g)
r 0.17
Age
t
p
r
p
0.02
0.08
0.25
Table 3 Predicting preterm birth and low birth weight by measured variables. Preterm birtha B Parityc Age T1 stress T1 depressive symptoms T1 anxiety T2 stress T2 depressive symptoms T2 anxiety T3 stress T3 depressive symptoms T3 anxiety a b c
2.37 0.17 0.004 0.19 0.28 0.03 0.10 0.22 0.03 0.06 0.01
Low birth weightb Wald
p
Exp (B)
7.91 5.27 0.005 6.66 6.31 0.15 1.78 2.95 0.17 0.37 0.01
0.01 0.02 0.94 0.01 0.01 0.70 0.18 0.09 0.68 0.54 0.94
0.09 1.18 1.00 1.21 0.76 0.97 0.91 1.25 0.97 0.95 1.01
B – – 0.02 0.05 0.07 0.02 0.04 0.26 0.07 0.13 0.17
Wald
p
Exp (B)
– – 0.03 0.39 1.24 0.03 0.11 5.26 0.21 1.38 4.06
– – 0.87 0.53 0.27 0.86 0.74 0.02 0.64 0.24 0.04
– – 1.02 1.05 1.07 1.02 1.04 0.77 1.08 0.88 1.19
Preterm birth was coded as 1 while mature was coded as 0. Low birth weight was coded as 1 while normal birth weight was coded as 0. Primipara was coded as 1 while multipara was coded as 0.
which investigated 624 Canadian women at 35–39 weeks of gestation.24 Martini et al. also found that maternal anxiety disorders were not associated with preterm birth, but they did not specify which gestational time period was under investigation.21 On the other hand, this present study found that low birth weight was influenced by anxiety at more than 30 weeks of gestation. Previous research also found that anxious pregnant women at the second trimester tended to have newborns with lower birth weights than did non-anxious pregnant women.25 Contrary findings that anxiety was not associated with low birth weight have also been reported. For example, Hall et al. found that prenatal anxiety at 35–39 gestational weeks was not a significant predictor of low birth weight.24 The different results among these studies may not be attributed to different measuring tools since they all used Spielberger’s State Anxiety Inventory to measure perceived anxiety22–24; there may be some other explanations for such discrepancies. For women, being pregnant is a unique experience of a lifetime; not only do their bodies change dramatically, but also their moods change incredibly. It is very likely that pregnant women experienced the anxiety in a different way that could not be measured using present structured instrument and was notstudied/understood. Some scholars have proposed to use pregnancy anxiety or pregnancy-specific anxiety when evaluating experiences of anxiety during pregnancy.8 We therefore suggest that psychometric professionals develop suitable tools to measure anxiety during pregnancy.
From this present research, preterm birth was influenced by prenatal depressive symptoms at 25–29 gestational weeks. Previous research also generated the same result with a population at 20–28 weeks’ gestation.23 Neggers et al. also found that maternal depression at 22–23 weeks was related to preterm birth.26 In addition, Field et al. found that depressed pregnant women at their second trimester also had a higher chance of birthing babies prematurely, although their specific gestational age was not specified in that study.25 It seems that the late second trimester is a critical time point for possible premature birth if pregnant women are depressed. As for the impact on low birth weight, this study yielded no predictive ability of depressive symptoms at any time point. Field et al. also found that depression at the second trimester was not related to low birth weight.25 However, the research conducted by Rahman et al. found a positive relationship between depression at the third trimester and low birth weight.27 This inconsistency might be due to different measuring tools, since both Field et al.’s25 study and this present research used the CES-D, whereas Rahman et al.27 used the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) for ICD-10 diagnoses of Depressive Disorder. Regardless of whether stress, depressive symptoms, and anxiety experienced by pregnant women can predict adverse birth outcomes, maternal mental health has gained increasing attention recently and certain interventions such as aerobicexercises, supportive programs, mindfulness meditation, relaxation techniques, and others28–31 that have shown positive effects on
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
reducing stress, depression, and/or anxiety may be implemented to help reduce the risk of preterm birth and/or low birth weight in psychologically vulnerable women during pregnancy. On the other hand, a review article has concluded that women who received midwife-led continuity of care were less likely to experience preterm birth.32 In the midwife-led model of care, midwives work closely side by side by planning, organising, and providing maternal care continuously to pregnant women throughout their pregnancy. Applying the midwife-led continuity model of care might work as a possible mechanism for reducing perinatal mental health burden and further explaining a reduction of preterm birth rate. The findings in this study are subject to a few limitations. First, the generalisability of research findings may be limited because the participants were recruited from one single hospital using nonprobability sampling. Second, it is difficult to compare the results across studies due to the different measurement instruments and gestational time periods used. Therefore, it is suggested that future research studies invite more participants from different settings and conduct more studies across countries with similar study designs to increase the generalisability and comparability. 5. Conclusion This prospective longitudinal study revealed that both preterm birth and low birth weight were predictable, in that preterm birth could be expected if pregnant women experienced depressive symptoms or anxiety during 25–29 gestational weeks, whereas expecting mothers with anxiety starting from 30 weeks had a higher chance of having babies with low birth weights. Therefore, we suggest that prenatal care visits incorporate psychological assessments, such as self-administered screening questionnaires, among pregnant women during their gestational weeks of 25–29, i.e. the late second trimester of pregnancy, for early detection and management of maternal mental distress. Conflicts of interest The authors declare that there are no conflicts of interest. Acknowledgement The authors would like to thank Chang Gung Medical Research Program, Taiwan (CMRPF6A0032) for funding the study. References 1. Goldenberg RL, Culhane JF, Iams JD, Romero R. Epidemiology and causes of preterm birth. Lancet 2008;371(9606):75–84. 2. Makhoul IR, Awad E, Tamir A, Weintraub Z, Rotschild A, Bader D, et al. Parental and perinatal factors affecting childhood anthropometry of very-low-birth-weight premature infants: a population-based survey. Acta Paediatr 2009;98(6):963–9. 3. Marks K, Reichman B, Lusky A, Zmora E, Israel Neonatal Network. Fetal growth and postnatal growth failure in very-low-birth weight infants. Acta Paediatr 2006;95(2):236–42. 4. Blencowe H, Cousens S, Oestergaard MZ, Chou D, Moller AB, Narwal R, et al. National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: a systematic analysis and implications. Lancet 2012;379(9832):2162–72. 5. Health Promotion Administration. Ministry of Health and Welfare of Taiwan. Health statistics database. 2010. Available from: https://olap.hpa.gov.tw/Search. aspx?menu=100000000006&KeyWord=%E6%96%B0%E7%94%9F%E5%85%92 [accessed 5.03.15]. 6. Sicuri E, Bardaji A, Sigauque B, Maixenchs M, Nhacolo A, Nhalungo D, et al. Costs associated with low birth weight in a rural area of southern Mozambique. PLoS ONE 2011;6(12):e28744.
5
7. Vrekoussis T, Kalantaridou SN, Mastorakos G, Zoumakis E, Makrigiannakis A, Syrrou M, et al. The role of stress in female reproduction and pregnancy: an update. Ann N Y Acad Sci 2010;1205:69–75. 8. Dunkel Schetter C, Tanner L. Anxiety, depression and stress in pregnancy: implication for mothers, children, research, and practice. Curr Opin Psychiatry 2012;25(2):141–8. 9. Grote NK, Bridge JA, Gavin AR, Melville JL, Iyengar S, Katon WJ. A meta-analysis of depression during pregnancy and the risk of preterm birth, low birth weight, and intrauterine growth restriction. Arch Gen Psychiatry 2010;67(10):1012–24. 10. Littleton HL, Breitkopf CR, Berenson AB. Correlates of anxiety symptoms during pregnancy and association with perinatal outcomes: a meta-analysis. Am J Obstet Gynecol 2007;196(5):424–32. 11. Littleton HL, Bye K, Buck K, Amacker A. Psychosocial stress during pregnancy and perinatal outcomes: a meta-analytic review. J Psychosom Obstet Gynecol 2010;31(4):219–28. 12. Gustavson K, von Soest T, Karevold E, Røysamb E. Attrition and generalizability in longitudinal studies: findings from a 15-year population-based study and a Monte Carlo simulation study. BMC Public Health 2012;12:918. 13. Cohen S, Williamson GM. Perceived stress in a probability sample of the United States. In: Spacapam S, Oskamp S, editors. The social psychology of health. Newbury Park, CA, USA: Sage; 1988. p. 31–67. 14. Radloff LS. The CES-D scale: a self-report depression scale for research in the general population. Appl Psychol Meas 1977;1(3):385–401. 15. Mao Q, Zhu L, Su X. A comparison of postnatal depression and related factors between Chinese new mothers and fathers. J Clin Nurs 2011;20(5–6):645–52. 16. Cheng CY, Pickler RH. Effects of stress and social support on postpartum health of Chinese mothers in the United States. Res Nurs Health 2009;32(6):582–91. 17. Zung WW. A rating instrument for anxiety disorders. Psychosomatics 1971;12(6): 371–9. 18. Tran TD, Tran T, La B, Fisher LJ. Screening for common perinatal mental disorders in women in the north of Vietnam: a comparison of three psychometric instruments. J Affect Disord 2011;133(1–2):281–93. 19. Huang Z, Hao J, Su P, Huang K, Xing X, Cheng D, et al. The impact of prior abortion on anxiety and depression symptoms during a subsequent pregnancy: data from a population-based cohort study in China. Klinik Psikofarmakol Bu¨lteni 2012;22:51–8. 20. Roy-Matton N, Moutquin J, Brown C, Nathalie C, Bell L. The impact of perceived maternal stress and other psychosocial risk factors on pregnancy complications. J Obstet Gynaecol Can 2011;33(4):344–52. 21. Martini J, Knappe S, Beesdo-Baum K, Lieb R, Wittchen HU. Anxiety disorders before birth and self-perceived distress during pregnancy: associations with maternal depression and obstetric, neonatal and early childhood outcomes. Early Hum Dev 2010;86(5):305–10. 22. Amiri FN, Mohamadpour RA, Salmalian H, Ahmadi AM. The association between prenatal anxiety and spontaneous preterm birth and low birth weight. Iran Red Crescent Med J 2010;12(6):650–4. 23. Dayan J, Creveuil C, Marks MN, Conroy S, Herlicoviez M, Dreyfus M, et al. Prenatal depression, prenatal anxiety, and spontaneous preterm birth: a prospective cohort study among women with early and regular care. Psychosom Med 2006;68:938–46. 24. Hall WA, Stoll K, Hutton EK, Brown H. A prospective study of effects of psychological factors and sleep on obstetric interventions, mode of birth, and neonatal outcomes among low-risk British Columbian women. BMC Pregnancy Childbirth 2012;12:78. 25. Field T, Diego M, Hernandez-Reif M, Figueiredo B, Deeds O, Ascencio A, et al. Comorbid depression and anxiety effects on pregnancy and neonatal outcome. Infant Behav Dev 2010;33(1):23–9. 26. Neggers Y, Goldenberg R, Cliver S, Hauth J. The relationship between psychosocial profile, health practices, and pregnancy outcomes. Acta Obstet Gynecol Scand 2006;85(3):277–85. 27. Rahman A, Bunn J, Lovel H, Creed F. Association between antenatal depression and low birth weight in a developing country. Acta Psychiatr Scand 2007;115(6): 481–6. 28. Robledo-Colonia AF, Sandoval-Restrepo N, Mosquera-Valderrama YF, EscobarHurtado C, Ramı´rez-Ve´lez R. Aerobic exercise training during pregnancy reduces depressive symptoms in nulliparous women: a randomised trial. J Physiother 2012;58:9–15. 29. Dunn C, Hanieh E, Roberts R, Powrie R. Mindful pregnancy and childbirth: effects of a mindfulness-based intervention on women’s psychological distress and well-being in the perinatal period. Arch Womens Ment Health 2012;15(2): 139–43. 30. Urech C, Fink NS, Hoesli I, Wilhelm FH, Bitzer J, Alder J. Effects of relaxation on psychobiological wellbeing during pregnancy: a randomized controlled trial. Psychoneuroendocrinology 2010;35(9):1348–55. 31. Kieffer EC, Caldwell CH, Welmerink DB, Welch KB, Sinco BR, Guzma´n JR. Effect of the healthy MOMs lifestyle intervention on reducing depressive symptoms among pregnant Latinas. Am J Community Psychol 2013;51(1–2):76–89. 32. Sandall J, Soltani H, Gates S, Shennan A, Devane D. Midwife-led continuity models versus other models of care for childbearing women. Cochrane Database Syst Rev 2015;(9). AN CD004667.
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
WOMBI-520; No. of Pages 5 Women and Birth xxx (2016) xxx–xxx
Contents lists available at ScienceDirect
Women and Birth journal homepage: www.elsevier.com/locate/wombi
ORIGINAL RESEARCH – QUANTITATIVE
Effects of prenatal maternal mental distress on birth outcomes Shwu-Ru Liou a, Panchalli Wang b, Ching-Yu Cheng a,* a b
College of Nursing, Chang Gung University of Science and Technology, Chiayi Campus, Taiwan Department of Obstetrics and Gynecology, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Taiwan
A R T I C L E I N F O
Article history: Received 9 October 2015 Received in revised form 18 February 2016 Accepted 29 March 2016 Keywords: Stress Anxiety Depression Premature birth Low birth weight
A B S T R A C T
Background: Adverse effects of maternal mental distress during pregnancy have been extensively investigated, but the impact of prenatal maternal mental distress at various time periods during pregnancy on birth outcomes is rarely discussed. By understanding the relationship between maternal mental distress and unfavourable birth outcomes throughout pregnancy, appropriate evidence-based preventative care or intervention may be adopted in a timely manner. Aim: This study intended to investigate the effects of maternal stress, anxiety, and depressive symptoms across pregnancy on preterm birth and low birth weight. Methods: With a prospective longitudinal design, this study used the 10-item Perceived Stress Scale, Center for Epidemiologic Studies Depression Scale, and Zung Self-reported Anxiety Scale to investigate 197 participants who, at greater than 24 gestational weeks, completed the self-administered questionnaires during regular checkups in a hospital in southern Taiwan. Descriptive statistics, Mann–Whitney U test/Kruskal–Wallis test, and hierarchical logistic regression were applied for data analysis. Findings: The study found that anxiety and depressive symptoms at 25–29 gestational weeks could predict preterm birth, and that anxiety at greater than 30 gestational weeks was able to predict low birthweight. However, stress was not able to predict any kind of negative birth outcomes. Conclusion: Adverse birth outcomes were somewhat predictable by maternal mental distress; therefore, we suggested that prenatal visits incorporate psychological assessment for early detection and management to prevent possible adverse birth outcomes. ß 2016 Australian College of Midwives. Published by Elsevier Australia (a division of Reed International Books Australia Pty Ltd). All rights reserved.
Summary of relevance: Problem
What this paper adds
The impact of prenatal maternal mental distress at various time periods during pregnancy on birth outcomes is rarely discussed.
Anxiety and depressive symptoms at 25–29 gestational weeks could predict preterm birth whereas anxiety at greater than 30 gestational weeks was able to predict infant low birth weight.
What is already known Certain prenatal negative psychosocial emotions may activate the hypothalamic–pituitary–adrenal (HPA) axis and further suppress the immune system of a pregnant woman; the chronicity and/or excessive activation of the HPA axis can lead to adverse health outcomes.
* Corresponding author at: College of Nursing, Chang Gung University of Science and Technology, No. 2, Chiapu Rd. West Sec., Putz City, Chiayi 613, Taiwan. Tel.: +886 5 362 8800x2603; fax: +886 5 362 8866. E-mail address: [email protected] (C.-Y. Cheng).
1. Introduction Certain psychological distress experienced by women during pregnancy may cause adverse effects on birth outcomes. Among various adverse birth outcomes, preterm birth and low birth weight have gained extensive attention. Preterm birth is a significant cause of neonatal morbidity and mortality.1 Most premature babies are born underweight, and those with very low birth weight often face medical conditions and are likely to have growth and development issues.2,3 In 2010, the estimated
http://dx.doi.org/10.1016/j.wombi.2016.03.004 1871-5192/ß 2016 Australian College of Midwives. Published by Elsevier Australia (a division of Reed International Books Australia Pty Ltd). All rights reserved.
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 2
S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
average preterm birth rate in 184 countries, excluding Taiwan, was 11.1%.4 Although premature birth rate (9.05%) in 2013 in Taiwan was lower compared to the global average figure, more than half of those premature infants (56.33%) were born with low birth weight.5 Due to the high costs of hospitalisation and treatment for premature birth or low birth weight,6 health researchers and professionals have tried to understand the causes and related factors of these two unfavourable birth outcomes. From a physiological point of view, certain prenatal maternal psychosocial factors such as stress and other negative emotions may activate the hypothalamic–pituitary–adrenal (HPA) axis and further suppress the immune system of a pregnant woman; the chronicity and/or excessive activation of the HPA axis can lead to adverse health outcomes, including preterm birth and low birth weight.7 Based on this aspect, many researchers devoted themselves to confirming the relationship between maternal mental distress (e.g. stress, anxiety, and depression) and negative birth outcomes (e.g. premature birth and low birth weight). However, the evidence linking maternal mental distress to adverse birth outcomes is inconclusive. While some studies have confirmed that stress, depression, or anxiety is related to prematurity or low birth weight, other studies yielded very small or non-significant evidence.8–11 Although the correlation has not yet been confirmed, adverse effects of maternal mental distress during pregnancy have been vastly investigated; yet the impact of prenatal maternal mental distress on birth outcomes at various time periods during pregnancy is rarely discussed. By understanding the relationship between maternal mental distress and unfavourable birth outcomes throughout pregnancy, proper preventative care or treatment intervention might be adopted at the right time for the right person. Therefore, we conducted this research to understand (a) whether adverse birth outcomes (i.e. preterm birth or low birth weight) can be predicted by prenatal maternal mental distress (i.e. stress, anxiety, or depressive symptoms), and (b) at what time during pregnancy can prenatal maternal mental distress predict adverse birth outcomes? In this present study, preterm birth was defined as births before 37 weeks of gestation and low birth weight was defined as weight at birth less than 2500 g.
2. Participants, ethics and methods 2.1. Pilot study A pilot test was first conducted to help determine proper sample size for the main study. The pilot study was a crosssectional study design. One-hundred thirty women who were pregnant over 24 gestational weeks were recruited to complete a set of questionnaires measuring anxiety, depressive symptoms, and stress. We found in the pilot study that the correlation coefficient between stress, depressive symptoms, and anxiety was between 0.45 and 0.66. Using the G*Power analysis program with critical value of 0.05 and two-tailed test, 47 and 16 participants respectively were needed to achieve a power of 90%. 2.2. Main study 2.2.1. Design This study used a prospective longitudinal design to explore the impact of prenatal maternal mental distress on birth outcomes. The participants were recruited when they were over 24 gestational weeks and were followed up monthly, finishing with a total of three survey times (T1: 25–29 gestational weeks, T2: 30–34 gestational weeks, T3: >34 gestational weeks).
2.2.2. Sampling Pregnant women who were 18 years of age or older, able to read and write Chinese, over 24 gestational weeks, singleton, and who did not have any pregnancy complications (including diagnosed psychological disorders) were invited to participate in the study. Based on the sample size estimated using the results of the pilot study and a high attrition rate anticipated due to the longitudinal design of this present study,12 we invited as many participants as possible during the study period between February 2010 and October 2011. In the beginning, 264 pregnant women were approached and 56 declined to participate. With 11 dropouts after the second survey, 197 participants completed the entire study (response rate = 74.62%). One participant did not complete the T2 survey and three did not complete the T3 survey due to preterm birth; therefore, there were 197, 196, and 194 valid questionnaires at T1, T2 and T3, respectively. There were no statistically significant differences in the demographic variables between those women that dropped out of the study and participants that were retained. 2.2.3. Instruments Three instruments were used to assess the participants’ levels of stress, depressive symptoms and anxiety. 2.2.3.1. Perceived stress. We used the 10-item Perceived Stress Scale (PSS-10) to measure the degree by which situations were appraised as stressful in one’s life.13 It is a 10-item, five-point scale, ranging from 0 to 4. A higher score on the PSS-10 indicates a higher level of perceived stress. The scale has been translated into Chinese and used among Chinese new mothers,14,15 and the reliability of the Chinese version was satisfactory (Cronbach’s alpha = 0.87). The Cronbach’s alpha of the PSS-10 in this study was 0.87. 2.2.3.2. Depressive symptoms. Developed by Radloff, the Center for Epidemiologic Studies Depression Scale (CES-D), a 20-item, fourpoint (scores 0–3) response, self-reported scale was used to measure the participants’ level of depressive symptoms. The higher the score, the greater the severity of depressive symptoms experienced.14 In Radloff’s original work, the cutoff point for depression was 16, with the Cronbach’s alphas ranging from 0.84 to 0.90, and the 2, 4, 6, and 8 weeks of test–retest correlations ranging from 0.51 to 0.67.14 The CES-D has been used in Chinese new mothers with satisfactory Cronbach’s alphas.15,16 The Cronbach’s alpha of the CES-D in this study was 0.89. 2.2.3.3. Perceived anxiety. Developed to evaluate the presence ofanxiety, the Zung Self-reported Anxiety Scale (SAS) is a 20-item, four-point (scores 1–4) scale.17 A higher score indicates a higher perceived level of anxiety. The SAS has been validated among Vietnamese women during perinatal period (Cronbach’s alpha = 0.76)18 and among Chinese women with a history of spontaneous abortion or induced abortion during a subsequent pregnancy with a satisfactory internal consistency (Cronbach’s alpha = 0.81).19 The reliability of the SAS in this study was tested using the data gathered at the first time period (25–29 gestational weeks). Results showed that the Cronbach’s alpha of the whole scale was 0.65, and two items (‘‘I can breathe in and out easily’’ and ‘‘I fall asleep easily and get a good night’s rest’’) had negative, low itemtotal correlation coefficients (r = 0.02 and 0.14, respectively). By deleting these two items, the Cronbach’s alpha increased to 0.72, and factor analysis showed that the remaining 18 items could explain 53.39% of the variance of anxiety. The 18-item SAS was therefore used in the study for subsequent data collections. 2.2.4. Procedure Before the study commenced, an approval of the study protocol from the Institutional Review Board was obtained by the
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
3
The prevalence rate of depressive symptoms experienced by the participants at T1, T2, and T3 was 25.9%, 25.5%, and 24.2% respectively, which indicated that around 25% of the participants experienced depressive symptoms during pregnancy. This present study can only generate point prevalence of depressive symptoms because the other two screening tools did not have a cutoff point. However, as shown in Table 1, the levels of anxiety and stress perceived by the participants were low, since all item mean scores of the PSS and SAS were below average.
participating hospital. Participants were recruited via professional referrals and personal contacts in a teaching hospital in southern Taiwan. A trained research assistant approached pregnant women who were about to receive prenatal checkups in the waiting area, and provided sufficient information including the purpose of the study and research subjects’ rights to those women. After signing the informed consent, all participants were asked to complete a set of paper questionnaires monthly; they could either complete the questionnaires in the outpatient waiting area or bring the questionnaires home to complete and return via addressed, postage paid envelopes. The questionnaires were kept confidential and contained a random-assigned number that could trace the participant by the researcher. Appointments for data collection were made in accordance with the dates of the participants’ prenatal checkups.
3.2. Comparing differences in measured variables by demographic groups Among the demographic variables, only age and parity were related to gestational weeks at birth; older women and multiparas were likely to give birth at earlier gestation with or without preterm than their counterparts. In contrast, none of the demographic variables were related to birth weight. The analysis of differences in measured variables by demographic groups is shown in Table 2.
2.3. Data analysis Collected data were managed and analysed using SPSS version 18.0. All data were examined for missing values and normality before inferential statistical analysis was conducted. Results showed that there was only one missing value on T3 PSS and the missing value was managed by using expectation–maximisation (EM) algorithm. All measured variables at all collecting time points were not normally distributed (Shapiro–Wilk statistics ranged 0.90–0.99, p ranged <0.001–0.04). Therefore, nonparametric statistical analyses were used. Descriptive statistics were used to understand the participants’ demographic information and levels of measured variables. The Mann–Whitney U test and Kruskal–Wallis test were used to compare differences in measured variables by demographic groups. Hierarchical logistic regression was used to test the predictive power of measured variables for preterm birth and low birth weight. In the logistic regression analysis, demographic variables that were related to preterm birth or low birth weight were entered in the first set, T1 measured variables were in the second set, T2 measured variables were in the third set, and T3 measured variables were in the fourth set.
3.3. Logistic regression analysis Table 3 illustrates the predictive ability of measured variables on birth outcomes. Parity, age, T1 depressive symptoms, and T1 anxiety could predict preterm birth, while T2 and T3 anxiety were able to predict low birth weight. Stress had no predictive power on either preterm birth or low birth weight.
4. Discussion From the results, it seemed that different maternal distress at different prenatal periods had various influences on birth outcomes: stress throughout pregnancy could not predict any forms of birth outcome, anxiety and depressive symptoms at T1 could predict premature birth, and anxiety at T2 and T3 could predict low birth weight. Contrary to expectations, we did not find that stress perceived by pregnant women at more than 24 weeks of gestation had any effect on either preterm birth or low birth weight. A previous research conducted by Roy-Matton et al. found that women with preterm birth perceived higher levels of stress before 20 gestational weeks than those with term pregnancy, but the perception was dismissed after 25 weeks.20 Although some researchers found a relationship between perceived stress and preterm birth, they did not specify what gestational stage was influential.21 Based on both the results yielded from Roy-Matton et al.20 and this present study, the impact of stress on preterm birth seems not to be significant at and after 25 weeks of pregnancy. We found that maternal anxiety at 25–29 gestational weeks had an impact on preterm birth. Amiri et al. also found that prenatal anxiety (20–28 weeks) was related to preterm birth22; however, Dayan et al. found no association between preterm birth and anxiety at the same time period (20–28 weeks).23 In addition, our finding that maternal anxiety at greater than 30 weeks was not able to predict preterm birth was consistent with a previous study,
3. Results 3.1. Descriptive statistics The mean age of the participants was 29.71 (SD = 4.42, range 19–42) years, and the mean gestational age during the first data collection time was 27.34 (SD = 1.08, range 25–29) weeks. The majority of the participants were primipara (56.3%). Almost all of the participants were married or cohabited (99.0%), and about half of them planned the index pregnancy (51.3%). About two thirds of the participants had an educational level of college or higher (68%), and most of the participants were employed (59.9%). Most participants gave birth vaginally (72.6%). The mean birth weight of the newborns was 3028.12 (SD = 341.43, range 1820–3940) g, and the mean gestational age at birth was 38.20 (SD = 1.37, range 32–41) weeks. Nineteen babies (9.6%) were born prematurely (<37 weeks), and 11 babies (5.6%) had a low birth weight (<2500 g). Table 1 Sample means of measured variables across different time periods. T2
T1
Stress Depressive symptoms Anxiety
T3
Scale M SD
Item M SD
Scale M SD
Item M SD
Scale M SD
Item M SD
17.17 5.21 11.16 8.32 41.28 7.53
1.72 0.52 0.56 0.42 2.06 0.38
16.46 5.18 11.53 8.04 43.69 6.75
1.65 0.52 0.58 0.40 2.18 0.34
16.30 5.16 11.16 7.89 43.62 7.51
1.63 0.52 0.56 0.39 2.18 0.38
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
4
Table 2 Comparison of gestational age at birth and birth weight by demographic variables. Gestational age at birth (weeks) M SD Parity Primipara Multipara Employment Employed Unemployed Education Less than college College or higher Planned pregnancy No Yes
Birth weight (g)
t
p
14.06
<0.001
M SD
38.68 1.10 37.59 1.45
p
1.89
0.22
0.99
1.00
0.10
0.75
1.04
0.36
3017.16 305.95 3042.26 383.82 0.001
1.00
38.16 1.37 38.28 1.38
3021.86 358.18 3038.97 312.36 0.002
1.00
38.22 1.43 38.19 1.35
3046.13 336.40 3019.65 344.70 0.02
1.00
38.29 1.52 38.12 1.21
3024.52 357.49 3031.53 327.20
Gestational age at birth (weeks)
Birth weight (g)
r 0.17
Age
t
p
r
p
0.02
0.08
0.25
Table 3 Predicting preterm birth and low birth weight by measured variables. Preterm birtha B Parityc Age T1 stress T1 depressive symptoms T1 anxiety T2 stress T2 depressive symptoms T2 anxiety T3 stress T3 depressive symptoms T3 anxiety a b c
2.37 0.17 0.004 0.19 0.28 0.03 0.10 0.22 0.03 0.06 0.01
Low birth weightb Wald
p
Exp (B)
7.91 5.27 0.005 6.66 6.31 0.15 1.78 2.95 0.17 0.37 0.01
0.01 0.02 0.94 0.01 0.01 0.70 0.18 0.09 0.68 0.54 0.94
0.09 1.18 1.00 1.21 0.76 0.97 0.91 1.25 0.97 0.95 1.01
B – – 0.02 0.05 0.07 0.02 0.04 0.26 0.07 0.13 0.17
Wald
p
Exp (B)
– – 0.03 0.39 1.24 0.03 0.11 5.26 0.21 1.38 4.06
– – 0.87 0.53 0.27 0.86 0.74 0.02 0.64 0.24 0.04
– – 1.02 1.05 1.07 1.02 1.04 0.77 1.08 0.88 1.19
Preterm birth was coded as 1 while mature was coded as 0. Low birth weight was coded as 1 while normal birth weight was coded as 0. Primipara was coded as 1 while multipara was coded as 0.
which investigated 624 Canadian women at 35–39 weeks of gestation.24 Martini et al. also found that maternal anxiety disorders were not associated with preterm birth, but they did not specify which gestational time period was under investigation.21 On the other hand, this present study found that low birth weight was influenced by anxiety at more than 30 weeks of gestation. Previous research also found that anxious pregnant women at the second trimester tended to have newborns with lower birth weights than did non-anxious pregnant women.25 Contrary findings that anxiety was not associated with low birth weight have also been reported. For example, Hall et al. found that prenatal anxiety at 35–39 gestational weeks was not a significant predictor of low birth weight.24 The different results among these studies may not be attributed to different measuring tools since they all used Spielberger’s State Anxiety Inventory to measure perceived anxiety22–24; there may be some other explanations for such discrepancies. For women, being pregnant is a unique experience of a lifetime; not only do their bodies change dramatically, but also their moods change incredibly. It is very likely that pregnant women experienced the anxiety in a different way that could not be measured using present structured instrument and was notstudied/understood. Some scholars have proposed to use pregnancy anxiety or pregnancy-specific anxiety when evaluating experiences of anxiety during pregnancy.8 We therefore suggest that psychometric professionals develop suitable tools to measure anxiety during pregnancy.
From this present research, preterm birth was influenced by prenatal depressive symptoms at 25–29 gestational weeks. Previous research also generated the same result with a population at 20–28 weeks’ gestation.23 Neggers et al. also found that maternal depression at 22–23 weeks was related to preterm birth.26 In addition, Field et al. found that depressed pregnant women at their second trimester also had a higher chance of birthing babies prematurely, although their specific gestational age was not specified in that study.25 It seems that the late second trimester is a critical time point for possible premature birth if pregnant women are depressed. As for the impact on low birth weight, this study yielded no predictive ability of depressive symptoms at any time point. Field et al. also found that depression at the second trimester was not related to low birth weight.25 However, the research conducted by Rahman et al. found a positive relationship between depression at the third trimester and low birth weight.27 This inconsistency might be due to different measuring tools, since both Field et al.’s25 study and this present research used the CES-D, whereas Rahman et al.27 used the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) for ICD-10 diagnoses of Depressive Disorder. Regardless of whether stress, depressive symptoms, and anxiety experienced by pregnant women can predict adverse birth outcomes, maternal mental health has gained increasing attention recently and certain interventions such as aerobicexercises, supportive programs, mindfulness meditation, relaxation techniques, and others28–31 that have shown positive effects on
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004
G Model
WOMBI-520; No. of Pages 5 S.-R. Liou et al. / Women and Birth xxx (2016) xxx–xxx
reducing stress, depression, and/or anxiety may be implemented to help reduce the risk of preterm birth and/or low birth weight in psychologically vulnerable women during pregnancy. On the other hand, a review article has concluded that women who received midwife-led continuity of care were less likely to experience preterm birth.32 In the midwife-led model of care, midwives work closely side by side by planning, organising, and providing maternal care continuously to pregnant women throughout their pregnancy. Applying the midwife-led continuity model of care might work as a possible mechanism for reducing perinatal mental health burden and further explaining a reduction of preterm birth rate. The findings in this study are subject to a few limitations. First, the generalisability of research findings may be limited because the participants were recruited from one single hospital using nonprobability sampling. Second, it is difficult to compare the results across studies due to the different measurement instruments and gestational time periods used. Therefore, it is suggested that future research studies invite more participants from different settings and conduct more studies across countries with similar study designs to increase the generalisability and comparability. 5. Conclusion This prospective longitudinal study revealed that both preterm birth and low birth weight were predictable, in that preterm birth could be expected if pregnant women experienced depressive symptoms or anxiety during 25–29 gestational weeks, whereas expecting mothers with anxiety starting from 30 weeks had a higher chance of having babies with low birth weights. Therefore, we suggest that prenatal care visits incorporate psychological assessments, such as self-administered screening questionnaires, among pregnant women during their gestational weeks of 25–29, i.e. the late second trimester of pregnancy, for early detection and management of maternal mental distress. Conflicts of interest The authors declare that there are no conflicts of interest. Acknowledgement The authors would like to thank Chang Gung Medical Research Program, Taiwan (CMRPF6A0032) for funding the study. References 1. Goldenberg RL, Culhane JF, Iams JD, Romero R. Epidemiology and causes of preterm birth. Lancet 2008;371(9606):75–84. 2. Makhoul IR, Awad E, Tamir A, Weintraub Z, Rotschild A, Bader D, et al. Parental and perinatal factors affecting childhood anthropometry of very-low-birth-weight premature infants: a population-based survey. Acta Paediatr 2009;98(6):963–9. 3. Marks K, Reichman B, Lusky A, Zmora E, Israel Neonatal Network. Fetal growth and postnatal growth failure in very-low-birth weight infants. Acta Paediatr 2006;95(2):236–42. 4. Blencowe H, Cousens S, Oestergaard MZ, Chou D, Moller AB, Narwal R, et al. National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: a systematic analysis and implications. Lancet 2012;379(9832):2162–72. 5. Health Promotion Administration. Ministry of Health and Welfare of Taiwan. Health statistics database. 2010. Available from: https://olap.hpa.gov.tw/Search. aspx?menu=100000000006&KeyWord=%E6%96%B0%E7%94%9F%E5%85%92 [accessed 5.03.15]. 6. Sicuri E, Bardaji A, Sigauque B, Maixenchs M, Nhacolo A, Nhalungo D, et al. Costs associated with low birth weight in a rural area of southern Mozambique. PLoS ONE 2011;6(12):e28744.
5
7. Vrekoussis T, Kalantaridou SN, Mastorakos G, Zoumakis E, Makrigiannakis A, Syrrou M, et al. The role of stress in female reproduction and pregnancy: an update. Ann N Y Acad Sci 2010;1205:69–75. 8. Dunkel Schetter C, Tanner L. Anxiety, depression and stress in pregnancy: implication for mothers, children, research, and practice. Curr Opin Psychiatry 2012;25(2):141–8. 9. Grote NK, Bridge JA, Gavin AR, Melville JL, Iyengar S, Katon WJ. A meta-analysis of depression during pregnancy and the risk of preterm birth, low birth weight, and intrauterine growth restriction. Arch Gen Psychiatry 2010;67(10):1012–24. 10. Littleton HL, Breitkopf CR, Berenson AB. Correlates of anxiety symptoms during pregnancy and association with perinatal outcomes: a meta-analysis. Am J Obstet Gynecol 2007;196(5):424–32. 11. Littleton HL, Bye K, Buck K, Amacker A. Psychosocial stress during pregnancy and perinatal outcomes: a meta-analytic review. J Psychosom Obstet Gynecol 2010;31(4):219–28. 12. Gustavson K, von Soest T, Karevold E, Røysamb E. Attrition and generalizability in longitudinal studies: findings from a 15-year population-based study and a Monte Carlo simulation study. BMC Public Health 2012;12:918. 13. Cohen S, Williamson GM. Perceived stress in a probability sample of the United States. In: Spacapam S, Oskamp S, editors. The social psychology of health. Newbury Park, CA, USA: Sage; 1988. p. 31–67. 14. Radloff LS. The CES-D scale: a self-report depression scale for research in the general population. Appl Psychol Meas 1977;1(3):385–401. 15. Mao Q, Zhu L, Su X. A comparison of postnatal depression and related factors between Chinese new mothers and fathers. J Clin Nurs 2011;20(5–6):645–52. 16. Cheng CY, Pickler RH. Effects of stress and social support on postpartum health of Chinese mothers in the United States. Res Nurs Health 2009;32(6):582–91. 17. Zung WW. A rating instrument for anxiety disorders. Psychosomatics 1971;12(6): 371–9. 18. Tran TD, Tran T, La B, Fisher LJ. Screening for common perinatal mental disorders in women in the north of Vietnam: a comparison of three psychometric instruments. J Affect Disord 2011;133(1–2):281–93. 19. Huang Z, Hao J, Su P, Huang K, Xing X, Cheng D, et al. The impact of prior abortion on anxiety and depression symptoms during a subsequent pregnancy: data from a population-based cohort study in China. Klinik Psikofarmakol Bu¨lteni 2012;22:51–8. 20. Roy-Matton N, Moutquin J, Brown C, Nathalie C, Bell L. The impact of perceived maternal stress and other psychosocial risk factors on pregnancy complications. J Obstet Gynaecol Can 2011;33(4):344–52. 21. Martini J, Knappe S, Beesdo-Baum K, Lieb R, Wittchen HU. Anxiety disorders before birth and self-perceived distress during pregnancy: associations with maternal depression and obstetric, neonatal and early childhood outcomes. Early Hum Dev 2010;86(5):305–10. 22. Amiri FN, Mohamadpour RA, Salmalian H, Ahmadi AM. The association between prenatal anxiety and spontaneous preterm birth and low birth weight. Iran Red Crescent Med J 2010;12(6):650–4. 23. Dayan J, Creveuil C, Marks MN, Conroy S, Herlicoviez M, Dreyfus M, et al. Prenatal depression, prenatal anxiety, and spontaneous preterm birth: a prospective cohort study among women with early and regular care. Psychosom Med 2006;68:938–46. 24. Hall WA, Stoll K, Hutton EK, Brown H. A prospective study of effects of psychological factors and sleep on obstetric interventions, mode of birth, and neonatal outcomes among low-risk British Columbian women. BMC Pregnancy Childbirth 2012;12:78. 25. Field T, Diego M, Hernandez-Reif M, Figueiredo B, Deeds O, Ascencio A, et al. Comorbid depression and anxiety effects on pregnancy and neonatal outcome. Infant Behav Dev 2010;33(1):23–9. 26. Neggers Y, Goldenberg R, Cliver S, Hauth J. The relationship between psychosocial profile, health practices, and pregnancy outcomes. Acta Obstet Gynecol Scand 2006;85(3):277–85. 27. Rahman A, Bunn J, Lovel H, Creed F. Association between antenatal depression and low birth weight in a developing country. Acta Psychiatr Scand 2007;115(6): 481–6. 28. Robledo-Colonia AF, Sandoval-Restrepo N, Mosquera-Valderrama YF, EscobarHurtado C, Ramı´rez-Ve´lez R. Aerobic exercise training during pregnancy reduces depressive symptoms in nulliparous women: a randomised trial. J Physiother 2012;58:9–15. 29. Dunn C, Hanieh E, Roberts R, Powrie R. Mindful pregnancy and childbirth: effects of a mindfulness-based intervention on women’s psychological distress and well-being in the perinatal period. Arch Womens Ment Health 2012;15(2): 139–43. 30. Urech C, Fink NS, Hoesli I, Wilhelm FH, Bitzer J, Alder J. Effects of relaxation on psychobiological wellbeing during pregnancy: a randomized controlled trial. Psychoneuroendocrinology 2010;35(9):1348–55. 31. Kieffer EC, Caldwell CH, Welmerink DB, Welch KB, Sinco BR, Guzma´n JR. Effect of the healthy MOMs lifestyle intervention on reducing depressive symptoms among pregnant Latinas. Am J Community Psychol 2013;51(1–2):76–89. 32. Sandall J, Soltani H, Gates S, Shennan A, Devane D. Midwife-led continuity models versus other models of care for childbearing women. Cochrane Database Syst Rev 2015;(9). AN CD004667.
Please cite this article in press as: Liou S-R, et al. Effects of prenatal maternal mental distress on birth outcomes. Women Birth (2016), http://dx.doi.org/10.1016/j.wombi.2016.03.004