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Acceptability of chorionic villi sampling for prenatal diagnosis
Urethral pressure and stress
Volume 155 Number I
7. Hilton P, Stanton SL. Urethral pressure measurement by microtransducers: the results in symptom free women and in those with genuine stress incontinence. Br J Obstet Gynaecol 1983;90:919. 8. Bunne G, Obrink A. Urethral closure pressure at stressa comparison between stress incontinent and ocontinent women. Urol Res 1978;6:127. 9. Chrystle CD, Charmel S, Copeland WE. Q-tip test for stress urinary incontinence. Obstet GynecoI1971;38:3I3.
10. Richardson DA. Use of vaginal pressure measurement in urodynamic testing. Obstet Gynecol 1985 (in press). II. Hodgkinson CPo Stress urinary incontinence-I970. AM J OBSTET GYNECOL 1970; 108: 1141. 12. Westby M, Asmussen M, Ulmsteri U. Location of maximum intraurethral pressure related to urogenital diaphragm in the female subject as studied by simultaneous urethrocystometry and voiding urethrocystography. AM J OBSTET GYNECOL 1982;144:408. 0
Acceptability of chorionic villi sampling for prenatal diagnosis Margaret M. McGovern, Ph.D., James D. Gol!Iberg, M.D., and Robert J. Desnick, Ph.D., M.D. New York, New York The factors that influence women in choosing between first-trimester chorionic villi sampling and second-trimester amniocentesis for prenatal diagnosis were investigated. Five hundred twenty women of advanced maternal age who had previously undergone prenatal diagnosis by amniocentesis ano were delivered of a normal infant were requested to complete a questionnaire concerning their attitudes toward amniocentesis and chorionic villi sampling. The majority of respondents indicated that the time at which chorionic villi sampling is performed (76%), the rapid availability of diagnostic-results (72%), and the type of abortion procedure available (68%) would make them choose this method. In contrast, the factors that influenced women to choose amniocentesis included the known low risk of spontaneous abortion (76%) and confidence in the skill of the obstetrician who would perform the procedure (56%). When all factors were considered together, 68% of the respondents chose amniocentesis based on the known low risk of spontaneous abortion, whereas for those who chose chorionic villi sampling (32%), the major criterion was the fact that the procedure is performed in the first trimester. However, 87% of women who preferred amniocentesis indicated that if the risk of spontaneous abortion associated with chorionic villi sampling were equal to or less than that of amniocentesis, they would choose chorionic villi sampling. These results indicate that for many women of advanced maternal age, the acceptability and the use of chorionic villi sampling will be dependent on the demonstration that the risk of fetal loss is low, approaching that of amniocentesis. (AM J OesTET GVNECOL 1986;155:25-9.)
Key words: Chorionic villi sampling, amniocentesis, prenatal diagnosis Recently a new method of obtaining fetal tissue for prenatal diagnosis, called chorionic villi sampling, has been developed.'o2 This procedure, which is performed at 8 to 12 weeks of pregnancy, involves the ultrasoundguided transcervical aspiration of a small amount of chorionic villi. This tissue is used directly or can be cultured for diagnostic chromosomal and/or biochemical analyses. Test results are usually available within 2 weeks, thereby providing rapid relief of parental anxiety when the fetus is found normal or, if a fetus with a genetic defect is detected, permitting the parents to choose a safer, easier termination of the pregnancy durFrom the Division of Medical Genetics and Maternal-Fetal Medicine, Mount Sinai School of Medicine. Received for publication July 22, 1985; revised December 5, 1985; accepted February 3, 1986. Reprint requests: Dr. Robert). Desnick, Mount Sinai School of Medicine, Fifth Ave. and 100th St., New York, NY 10029.
ing the first trimester. Preliminary data from 10,000 procedures performed worldwide have revealed that chorionic villi sampling is safe for the mother and that the rate of fetal loss is about 4% when performed by experienced obstetricians. Since most conditions that can be diagnosed by amniocentesis are detectable by chorionic villi sampling, this procedure represents an attractive alternative to amniocentesis, which cannot be safely performed until the second trimester. Previous studies have documented the safety and accuracy of amniocentesis for prenatal diagnosis. 3o ' However, experience has identified several disadvantages of the procedure. Amniocentesis cannot be safely performed until the second trimester of pregnancy, usually during weeks 16 to 18, and the diagnostic results are often unavailable for 2 to 4 weeks after the procedure. Several investigators have reported that the period of waiting for the
25
26
McGovern, Goldberg, and Desnick
July, 1986 Am J Obstet Gynecol
Table I. Sources of stress or anxiety during prenatal diagnosis by amniocentesis Response (% of women)
1 (none)
Anxiety about a genetic defect being discovered Anxiety about the procedure itself Stress during the procedure Anxiety while waiting for resuits Relief after receipt of test resuits Overall anxiety during the pregnancy
3
I
2
I
(moderate)
5
I
4
I
(extreme)
Mean
SD
5
15
61
12
7
2.95
0.80
14
27
36
11
13
2.94
1.04
36 6
23 14
28 49
4 15
10
15
2.33 3.12
1.27 1.04
13
30
56
4.42
0.76
38
15
17
2.84
1.20
O
5
24
diagnostic results is the most psychologically stressful aspect of amniocentesis for most women and their partners.'-" In addition, if the results of the chromosomal and/or biochemical analyses reveal an abnormality and the woman chooses to terminate the pregnancy, a second-trimester abortion must be performed, which carries increased maternal morbidity and mortality, particularly with regard to the psychological trauma."" Chorionic villi sampling obviates many of the disadvantages associated with amniocentesis, since chorionic villi sampling is performed in the first trimester and the test results are usually available within 1 to 2 weeks. In this report, the acceptability of chorionic villi sampling versus amniocentesis was investigated by a retrospective study of a population of women who had previously undergone prenatal diagnosis by amniocentesis for the indication of advanced maternal age. Since each of these women had received preamniocentesis genetic counseling and subsequently undergone a successful amniocentesis and were delivered of a normal infant, they were familiar with this method of prenatal diagnosis from which they could compare and subjectively evaluate chorionic villi sampling for fetal diagnoses. Methods
Patient population. This study included 520 women of advanced maternal age who underwent amniocentesis at the Mount Sinai School of Medicine between April 1, 1983, and March 31, 1984, and who subsequently gave birth to a normal infant. In all of the subjects, advanced maternal age was the only indication for prenatal diagnosis (age-specific risk ranged from 0.4% to 3.2%). The mean age of the women was 36.91 years (range, 34 to 44 years) with a racial distribution of76%, white; 12%, black; 7%, Hispanic; and 4% Asian. Religious affiliations were 56%, Jewish; 22%, Catholic; 14%, Protestant; and 8%, other or none. Study design. The name, address, age, marital status,
race, history of previous pregnancies and induced and spontaneous abortions, and religious affiliation were obtained from each patient's record. A questionnaire consisting of 70 open- and closed-ended questions was devised to obtain demographic data and to assess the acceptability of chorionic villi sampling versus amniocentesis for prenatal diagnosis by asking the participants to identify and rank various factors that would influence their choice between chorionic villi sampling and amniocentesis. A questionnaire was mailed to each subject accompanied by a cover letter that requested participation and assured confidentiality and by a description of amniocentesis and chorionic villi sampling. The information provided about each procedure included its possible discomforts, the time at which the procedure is performed, the period of waiting for the diagnostic results, the risk of spontaneous abortion, and the type of abortion that could be performed (if the fetus were affected). Results Characteristics of the study population. Of the 520 women who were contacted by mail, 365 completed and returned the questionnaire, resulting in a response rate of 70%. There was no significant difference (p 3 0.5) in the mean age, religious affiliation, or gravidity ofthe responders and nonresponders to the questionnaire. The mean age of the participants was 37.07 years (± 1 SD = 2.32; range = 34 to 44), 98.3% were married, and 87% had some college or graduate school education. The distribution of religious affiliations were 53%, Jewish; 22%, Catholic; 13%, Protestant; and 12%, other or none. Only 8.6% of the responders had more than one amniocentesis. Experience with amniocentesis. Each of the respondents was asked about her recent prenatal diagnostic experience with amniocentesis. Eighty-one percent had planned the pregnancy and ofthese, 50% indicated that the availability of amniocentesis to monitor prenatally
Chorionic villi sampling for prenatal diagnosis
Volume 155 Number 1
27
Table II. The influence of various factors on choosing amniocentesis or chorionic villi sampling for prenatal diagnosis Response (% of women)
Factor
Risk of spontaneous abortion Risk of fetal damage Confidence in skill of physician Confidence in test results Discomfort during procedure Cost Time of procedure Type of abortion available Period of waiting for test results
"Would make me choose amniocentesis"
76 67
"Would make me choose chorionic villi sampling"
"Would make no difference"
8
16
24
56 39
9 3 10
37
8
14 9 6 5
76 68
the status of the fetus was a factor in their decision to become pregnant. Some respondents first learned about amniocentesis from the media (36%), their obstetricians (36%), or from friends or relatives (14%), whereas others (14%) reported that the availability of amniocentesis was "common knowledge." It was notable that 86% of respondents had sought prenatal care by the eighth week of pregnancy (mean ± 1 SD = 5.77 ± 3.13 weeks; range = 1 to 16 weeks), whereas only 37% of women received genetic counseling by the eighth week, with most (63%) seeking prenatal diagnosis during the ninth to seventeenth week of pregnancy (mean ± 1 SD = 9.48 ± 3.90 weeks; range = 1 to 18 weeks), presumably reflecting the fact that amniocentesis is usually performed after the sixteenth week of pregnancy. The maJor concerns of the respondents before amniocentesis included fear that the test would reveal an abnormality (86%), distress over the possibility that they may have to consider termination of the pregnancy (47%), concern that the fetus would be injured during the procedure (47%), worry that the procedure would cause a spontaneous abortion (37%), and fear of procedure-related discomfort or pain (28%). After amniocentesis the only reported complications included cramps and/or bleeding for several hours (2% of women). The respondents indicated that they received the results of the chromosome studies in 2 to 7 weeks, with an average wait of 3.24 weeks (± 1 SD = ± 1.07 weeks). Seventy-nine percent of respondents stated that they would have terminated the pregnancy if an abnormality had been discovered, whereas 19% were undecided and only 2% would have continued the pregnancy. The amount of stress and anxiety experienced before, during, and after the amniocentesis and the amount of relief experienced after the diagnostic results were known were assessed. As summarized in Table I, 81 % reported that they were only somewhat (that is, moderately or less than moderately) anxious
o
72
41 51 55
86 15
26 23
that their baby might be affected with a genetic disease. Seventy-seven percent of respondents indicated that they were somewhat anxious before amniocentesis, and 86% found the procedure somewhat stressful. In contrast, 83% were moderately or more than moderately anxious during the period while awaiting results, and all but two respondents reported moderate to extreme relief after the diagnostic results were known. Overall, prenatal diagnosis was described as a moderately anxious experience. Attitudes toward prenatal diagnosis in future pregnancies. Ninety-three percent of respondents indicated that they would definitely seek prenatal diagnosis in a future pregnancy, but the others were undecided. In addition, when asked if they would consider chorionic villi sampling instead of amniocentesis, 45% indicated that they would consider chorionic villi sampling, 20% would not, and 35% were undecided. Respondents were asked to consider separately a series of nine factors and to indicate how each factor would influence their choice between amniocentesis or chorionic villi sampling (Table II). The factors that influenced most respondents to choose amniocentesis included the known low-risk of spontaneous abortion or fetal damage and confidence in the physician's skill in performing the procedure. In contrast, the performance of the procedure during the first trimester of pregnancy, the shorter period of waiting for the diagnostic results, and the type of abortion procedure available in the first trimester were the factors that would influence most of the women to choose chorionic villi sampling. Factors that were not important in choosing between chorionic villi sampling and amniocentesis included the d'iscomfort or pain experienced during the procedure, confidence in the accuracy of the test results, and the cost of the procedure. When asked to consider all of the factors together and to indicate which procedure they would choose if faced with the decision, 68% of the respondents chose amniocentesis and 32% chose chorionic villi sampling,
28 McGovern, Goldberg, and Desnick
July, 1986 Am J Obstet Gynecol
Table III. Identification of the critical factors in choosing between amniocentesis or chorionic villi sampling Choice indicated by respondent (% of women) Factor
Amniocentesis
Chorionic villi sampling
Risk of fetal damage Risk of spontaneous abortion Confidence in test results Confidence in the skill of physician Discomfort during procedure Type of abortion available Time of procedure Period of waiting for results
51
8
47
4
41
4
25
7
19 9
0 0 44
9
69
7
II
II
The major factors involved in this decision are summarized in Table III. Respondentswho chose amniocentesis indicated their decision was based on the known low risk of damage to the fetus (51 %) or risk of spontaneous abortion (47%) and confidence in the test results (41 %). The major factors that influenced the respondents to select chorionic villi sampling were the time at which the procedure is done (69%), the type of abortion procedure available (44%), and the shorter waiting period to obtain the results (11 %). Of interest was the finding that most respondents who chose amniocentesis indicated that they would consider (47%) or choose (40%) chorionic villi sampling if the risk of spontaneous abortion resulting from this procedure were shown to be no more than that of amniocentesis. Since the women who participated in this study had previously undergone amniocentesis, it was likely that this experience influenced their attitudes about prenatal diagnosis and the choice between amniocentesis and chorionic villi sampling for a future pregnancy. To determine whether stress and anxiety experienced in the previous prenatal diagnosis significantly affected the choice between the two procedures, a X2 analysis of the data was performed. Among respondents .who reported that amniocentesis was "extremely stressful" there was a statistically significant increase in selecting chorionic villi sampling over respondents who found amniocentesis to be moderately or not at all stressful (0.05 > p> 0.02; a = 0.05). In contrast, those respondents who waited a relatively longer time (>3 weeks) to receive diagnostic results did not preferentially choose chorionic villi sampling when compared to those who had waited a shorted period «3 weeks) for the
test results (0.50 > P > 0.10). Similarly, the educational level bf the respondents (that is, high school versus college versus graduate school) did not significantly influence their choice (0.50> P > 0.10; a = 0.05).
Comment Health care providers have become increasingly aware of patient consumerism and the impact of patient preferences on the use of diagnostic techniques, participation in screening programs, and compliance with treatment regimens. Thus the comparison of the acceptabiiity of chorionic villi sampling versus amniocentesis to women at an increased risk of having a child with a genetic defect is important for estimating the future use of chorionic villi sampling for prenatal diagnosis. In addition, the identification of the critical factors that influence women choosing between chorionic villi sampling and amniocentesis may provide the basis for the further development and improved delivery of both techniques. Therefore a retrospective study of 365 women of advanced maternal age who had previously undergone amniocentesis was conducted to assess the attitudes of potential users toward chorionic villi sampling and to determine its acceptability compared to that of amniocentesis. The demographic characteristics of the participants were similar to those reported for patients seeking prenatal diagnosis at other testing centers in New York City and in other areas of the United States. 12• 15 The concerns of the respondents before undergoing amniocentesis in their most recent pregnancy included fear that the fetus would be harmed, that a spontaneous abortion would occur, or that an abnormality might be discovered. These concerns were similar to those reported by Doherty and Rice l5 for a: population who sought prenatal diagnosis in Rochester, New York. In addition, the respondents reported a high level of anxiety during the period of waiting for diagnostic results after amniocentesis (79% reported moderate to extreme anxiety) and a sense of relief after being informed that the chromosomal studies were normal (99% reported moderate to extreme relief). These findings were similar to those observed by other investigators. 5 . 6 The respondents in the present study also had similar concerns and anxieties before, during, and after amniocentesis and a comparable knowledge of the procedure when compared to participants in previous studies of amniocentesis. 5 .' Thus it was of interest to determine whether these women would choose amniocentesis or chorionic villi sampling for future prenatal diagnoses and to identify the factors that influenced the women in their choice. Most respondents indicated that the time at which the procedure is done, the shorter period of waiting for diagnostic results, and the type of abortion available
Volume 155 Number 1
would make them choose chorionic villi sampling (Table II). In contrast, most respondents indicated that the lower incidence of spontaneous abortion after amniocentesis and their confidence in the obstetrician's skill in performing the procedure would influence them to choose amniocentesis. For 86% of respondents, cost was not an important factor. When all factors were considered together and the women were asked to make a final choice between chorionic villi sampling and amniocentesis, 68% chose amniocentesis. For most respondents this decision was based on the known low risk of spontaneous abortion resulting from amniocentesis and the concern that chorionic villi sampling may in some way harm the fetus (Table III). Of interest was the fact that the majority of respondents whose final choice was amniocentesis indicated that they would consider or choose chorionic villi sampling, provided that the risk of spontaneous abortion resulting from chorionic villi sampling were less or equal to that associated with amniocentesis. For respondents whose final choice was chorionic villi sampling, the major influencing factors included the time at which the procedure was done and the type of abortion procedure available. Of interest was the finding that only 11 % of the women said that the shorter period of waiting for the test results was a factor in their decision to choose chorionic villi sampling. Therefore, despite the fact that numerous studies'-7 have documented the extreme stress that women experience while awaiting for diagnostic results, this did not appear to be a critical factor in selecting chorionic villi sampling rather than amniocentesis. Thus the respondents who chose amniocentesis were most concerned with the safety of the fetus, whereas women who chose chorionic villi sampling were most concerned with the time at which the procedure was done and the type of abortion procedure available. It was possible that the relative concerns of these two groups of women were determined by their ages, with older women more concerned with safeguarding the continuance of the pregnancy or by their past history of spontaneous abortions. However, the two groups did not differ significantly in either of these parameters (average age = 36.91 versus 36.78 and average number of spontaneous abortions = 0.41 versus 0.38 for those who chose amniocentesis and chorionic villi sampling, respectively). Another possible difference between the two groups, which was not assessed in this study, was the prior history of fertility and ease of conceiving, since women who have experienced fertility problems may be less willing to risk a spontaneous abortion. Since women of advanced maternal age represent the majority of women seeking prenatal diagnosis, the findings of this study provide insight into the relative ac-
Chorionic villi sampling for prenatal diagnosis
29
ceptabilities of chorionic villi sampling and amniocentesis. However, women who are at risk for having a child with a genetic defect and are at a higher risk (for example, when both members of a couple are carriers of a recessive disorder) may be more concerned with the timing of the procedure and the type and safety of the abortion procedure available should they elect to terminate an affected pregnancy. Thus it is likely that the acceptability of chorionic villi sampling to such individuals will be greater than for women in whom advanced maternal age is the only indication. In addition, the availability of chorionic villi sampling and the fact that this method permits termination of an affected pregnancy in the first trimester may result in use of this service by women who in the past have not sought prenatal diagnosis by amniocentesis because of religious and moral objections to second-trimester induced abortion. REFERENCES J. Kazy Z, Rozovsky IS, Bakharev VA_ Chorion biopsy in early pregnancy: a method of early prenatal diagnosis for inherited disorders. Pre nat Diagn 1982;2:39-45. 2. Rodeck CH, Morsmen]M. First trimester chorion biopsy. Br Med Bull 1983;39:338-42. 3. NICHD Study Group, National Registry for Amniocentesis. Midtrimester amniocentesis for prenatal diagnosis. ]AMA 1980;236:1471-6. 4. Simpson NR, Dallaire L, Miller ]R, et al. Prenatal diagnosis of genetic disease in Canada: report of a collaborative study. Can Med Assoc] 1976; 115:739-50. 5. Beeson D, Golbus M. Anxiety engendered by amniocentesis. Birth Defects 1979;15:191-7. 6. Golbus M, Conte F, Schneider E, Epstein G. Intrauterine diagnosis of genetic defects: results, problems, and followup of one hundred cases in a prenatal genetic detection center. AM] OBSTET GY:>iECOL 1974;118:897-905. 7. Rice N, Doherty R. Reflections on prenatal diagnosis: the consumers' views. Soc Work Health Care 1982;8:47-57. 8. Dixson B, Richards T, Reirsch S, Edrich V, Matson M, Jones O. Midtrimester amniocentesis: subjective maternal responses. ] Reprod Med 1981 ;26: 10-6. 9. Blumberg RD, Golbus M, Hanson K. The psychological sequelae of abortion performed for a genetic indication. AM] OBSTET GYNECOL 1975;122:799-808. 10. Niswander K, Patterson R. Psychological reaction to therapeutic abortion. Obstet Gynecol 1967;29:702-6. I I. Peek A, Marcus H. Psychological sequelae of therapeutic interruption of pregnancy. ] Nerv Ment Dis 1966; 143:417-26. 12. Marion ]P, Kassam G, Fernhoff P, et al. Acceptance of amniocentesis by low-income patients in an urban hospital. AM] OBSTET GYNECOL 1980;138:11-5. 13. Lippman-Hand A, Piper M. Prenatal diagnosis for the detection of Down syndrome: why are so few eligible women tested. Prenat Diagn 1981;1:249-57. 14. ]ahiel RI, Hansen H. Utilization of prenatal chromosome diagnosis in New York City, 1969-1979. Underrepresentation of older women and clinic patients. Am] Hum Genet 1980;32:112A. 15. Doherty RA, Rice N. Knowledge, attitudes and acceptance of prenatal diagnosis among women and physicians in the Rochester region. In: Porter LH, Hook FB, eds. New York: Academic Press, Service and education in medical genetics, 1979:120-34.
Volume 155 Number I
7. Hilton P, Stanton SL. Urethral pressure measurement by microtransducers: the results in symptom free women and in those with genuine stress incontinence. Br J Obstet Gynaecol 1983;90:919. 8. Bunne G, Obrink A. Urethral closure pressure at stressa comparison between stress incontinent and ocontinent women. Urol Res 1978;6:127. 9. Chrystle CD, Charmel S, Copeland WE. Q-tip test for stress urinary incontinence. Obstet GynecoI1971;38:3I3.
10. Richardson DA. Use of vaginal pressure measurement in urodynamic testing. Obstet Gynecol 1985 (in press). II. Hodgkinson CPo Stress urinary incontinence-I970. AM J OBSTET GYNECOL 1970; 108: 1141. 12. Westby M, Asmussen M, Ulmsteri U. Location of maximum intraurethral pressure related to urogenital diaphragm in the female subject as studied by simultaneous urethrocystometry and voiding urethrocystography. AM J OBSTET GYNECOL 1982;144:408. 0
Acceptability of chorionic villi sampling for prenatal diagnosis Margaret M. McGovern, Ph.D., James D. Gol!Iberg, M.D., and Robert J. Desnick, Ph.D., M.D. New York, New York The factors that influence women in choosing between first-trimester chorionic villi sampling and second-trimester amniocentesis for prenatal diagnosis were investigated. Five hundred twenty women of advanced maternal age who had previously undergone prenatal diagnosis by amniocentesis ano were delivered of a normal infant were requested to complete a questionnaire concerning their attitudes toward amniocentesis and chorionic villi sampling. The majority of respondents indicated that the time at which chorionic villi sampling is performed (76%), the rapid availability of diagnostic-results (72%), and the type of abortion procedure available (68%) would make them choose this method. In contrast, the factors that influenced women to choose amniocentesis included the known low risk of spontaneous abortion (76%) and confidence in the skill of the obstetrician who would perform the procedure (56%). When all factors were considered together, 68% of the respondents chose amniocentesis based on the known low risk of spontaneous abortion, whereas for those who chose chorionic villi sampling (32%), the major criterion was the fact that the procedure is performed in the first trimester. However, 87% of women who preferred amniocentesis indicated that if the risk of spontaneous abortion associated with chorionic villi sampling were equal to or less than that of amniocentesis, they would choose chorionic villi sampling. These results indicate that for many women of advanced maternal age, the acceptability and the use of chorionic villi sampling will be dependent on the demonstration that the risk of fetal loss is low, approaching that of amniocentesis. (AM J OesTET GVNECOL 1986;155:25-9.)
Key words: Chorionic villi sampling, amniocentesis, prenatal diagnosis Recently a new method of obtaining fetal tissue for prenatal diagnosis, called chorionic villi sampling, has been developed.'o2 This procedure, which is performed at 8 to 12 weeks of pregnancy, involves the ultrasoundguided transcervical aspiration of a small amount of chorionic villi. This tissue is used directly or can be cultured for diagnostic chromosomal and/or biochemical analyses. Test results are usually available within 2 weeks, thereby providing rapid relief of parental anxiety when the fetus is found normal or, if a fetus with a genetic defect is detected, permitting the parents to choose a safer, easier termination of the pregnancy durFrom the Division of Medical Genetics and Maternal-Fetal Medicine, Mount Sinai School of Medicine. Received for publication July 22, 1985; revised December 5, 1985; accepted February 3, 1986. Reprint requests: Dr. Robert). Desnick, Mount Sinai School of Medicine, Fifth Ave. and 100th St., New York, NY 10029.
ing the first trimester. Preliminary data from 10,000 procedures performed worldwide have revealed that chorionic villi sampling is safe for the mother and that the rate of fetal loss is about 4% when performed by experienced obstetricians. Since most conditions that can be diagnosed by amniocentesis are detectable by chorionic villi sampling, this procedure represents an attractive alternative to amniocentesis, which cannot be safely performed until the second trimester. Previous studies have documented the safety and accuracy of amniocentesis for prenatal diagnosis. 3o ' However, experience has identified several disadvantages of the procedure. Amniocentesis cannot be safely performed until the second trimester of pregnancy, usually during weeks 16 to 18, and the diagnostic results are often unavailable for 2 to 4 weeks after the procedure. Several investigators have reported that the period of waiting for the
25
26
McGovern, Goldberg, and Desnick
July, 1986 Am J Obstet Gynecol
Table I. Sources of stress or anxiety during prenatal diagnosis by amniocentesis Response (% of women)
1 (none)
Anxiety about a genetic defect being discovered Anxiety about the procedure itself Stress during the procedure Anxiety while waiting for resuits Relief after receipt of test resuits Overall anxiety during the pregnancy
3
I
2
I
(moderate)
5
I
4
I
(extreme)
Mean
SD
5
15
61
12
7
2.95
0.80
14
27
36
11
13
2.94
1.04
36 6
23 14
28 49
4 15
10
15
2.33 3.12
1.27 1.04
13
30
56
4.42
0.76
38
15
17
2.84
1.20
O
5
24
diagnostic results is the most psychologically stressful aspect of amniocentesis for most women and their partners.'-" In addition, if the results of the chromosomal and/or biochemical analyses reveal an abnormality and the woman chooses to terminate the pregnancy, a second-trimester abortion must be performed, which carries increased maternal morbidity and mortality, particularly with regard to the psychological trauma."" Chorionic villi sampling obviates many of the disadvantages associated with amniocentesis, since chorionic villi sampling is performed in the first trimester and the test results are usually available within 1 to 2 weeks. In this report, the acceptability of chorionic villi sampling versus amniocentesis was investigated by a retrospective study of a population of women who had previously undergone prenatal diagnosis by amniocentesis for the indication of advanced maternal age. Since each of these women had received preamniocentesis genetic counseling and subsequently undergone a successful amniocentesis and were delivered of a normal infant, they were familiar with this method of prenatal diagnosis from which they could compare and subjectively evaluate chorionic villi sampling for fetal diagnoses. Methods
Patient population. This study included 520 women of advanced maternal age who underwent amniocentesis at the Mount Sinai School of Medicine between April 1, 1983, and March 31, 1984, and who subsequently gave birth to a normal infant. In all of the subjects, advanced maternal age was the only indication for prenatal diagnosis (age-specific risk ranged from 0.4% to 3.2%). The mean age of the women was 36.91 years (range, 34 to 44 years) with a racial distribution of76%, white; 12%, black; 7%, Hispanic; and 4% Asian. Religious affiliations were 56%, Jewish; 22%, Catholic; 14%, Protestant; and 8%, other or none. Study design. The name, address, age, marital status,
race, history of previous pregnancies and induced and spontaneous abortions, and religious affiliation were obtained from each patient's record. A questionnaire consisting of 70 open- and closed-ended questions was devised to obtain demographic data and to assess the acceptability of chorionic villi sampling versus amniocentesis for prenatal diagnosis by asking the participants to identify and rank various factors that would influence their choice between chorionic villi sampling and amniocentesis. A questionnaire was mailed to each subject accompanied by a cover letter that requested participation and assured confidentiality and by a description of amniocentesis and chorionic villi sampling. The information provided about each procedure included its possible discomforts, the time at which the procedure is performed, the period of waiting for the diagnostic results, the risk of spontaneous abortion, and the type of abortion that could be performed (if the fetus were affected). Results Characteristics of the study population. Of the 520 women who were contacted by mail, 365 completed and returned the questionnaire, resulting in a response rate of 70%. There was no significant difference (p 3 0.5) in the mean age, religious affiliation, or gravidity ofthe responders and nonresponders to the questionnaire. The mean age of the participants was 37.07 years (± 1 SD = 2.32; range = 34 to 44), 98.3% were married, and 87% had some college or graduate school education. The distribution of religious affiliations were 53%, Jewish; 22%, Catholic; 13%, Protestant; and 12%, other or none. Only 8.6% of the responders had more than one amniocentesis. Experience with amniocentesis. Each of the respondents was asked about her recent prenatal diagnostic experience with amniocentesis. Eighty-one percent had planned the pregnancy and ofthese, 50% indicated that the availability of amniocentesis to monitor prenatally
Chorionic villi sampling for prenatal diagnosis
Volume 155 Number 1
27
Table II. The influence of various factors on choosing amniocentesis or chorionic villi sampling for prenatal diagnosis Response (% of women)
Factor
Risk of spontaneous abortion Risk of fetal damage Confidence in skill of physician Confidence in test results Discomfort during procedure Cost Time of procedure Type of abortion available Period of waiting for test results
"Would make me choose amniocentesis"
76 67
"Would make me choose chorionic villi sampling"
"Would make no difference"
8
16
24
56 39
9 3 10
37
8
14 9 6 5
76 68
the status of the fetus was a factor in their decision to become pregnant. Some respondents first learned about amniocentesis from the media (36%), their obstetricians (36%), or from friends or relatives (14%), whereas others (14%) reported that the availability of amniocentesis was "common knowledge." It was notable that 86% of respondents had sought prenatal care by the eighth week of pregnancy (mean ± 1 SD = 5.77 ± 3.13 weeks; range = 1 to 16 weeks), whereas only 37% of women received genetic counseling by the eighth week, with most (63%) seeking prenatal diagnosis during the ninth to seventeenth week of pregnancy (mean ± 1 SD = 9.48 ± 3.90 weeks; range = 1 to 18 weeks), presumably reflecting the fact that amniocentesis is usually performed after the sixteenth week of pregnancy. The maJor concerns of the respondents before amniocentesis included fear that the test would reveal an abnormality (86%), distress over the possibility that they may have to consider termination of the pregnancy (47%), concern that the fetus would be injured during the procedure (47%), worry that the procedure would cause a spontaneous abortion (37%), and fear of procedure-related discomfort or pain (28%). After amniocentesis the only reported complications included cramps and/or bleeding for several hours (2% of women). The respondents indicated that they received the results of the chromosome studies in 2 to 7 weeks, with an average wait of 3.24 weeks (± 1 SD = ± 1.07 weeks). Seventy-nine percent of respondents stated that they would have terminated the pregnancy if an abnormality had been discovered, whereas 19% were undecided and only 2% would have continued the pregnancy. The amount of stress and anxiety experienced before, during, and after the amniocentesis and the amount of relief experienced after the diagnostic results were known were assessed. As summarized in Table I, 81 % reported that they were only somewhat (that is, moderately or less than moderately) anxious
o
72
41 51 55
86 15
26 23
that their baby might be affected with a genetic disease. Seventy-seven percent of respondents indicated that they were somewhat anxious before amniocentesis, and 86% found the procedure somewhat stressful. In contrast, 83% were moderately or more than moderately anxious during the period while awaiting results, and all but two respondents reported moderate to extreme relief after the diagnostic results were known. Overall, prenatal diagnosis was described as a moderately anxious experience. Attitudes toward prenatal diagnosis in future pregnancies. Ninety-three percent of respondents indicated that they would definitely seek prenatal diagnosis in a future pregnancy, but the others were undecided. In addition, when asked if they would consider chorionic villi sampling instead of amniocentesis, 45% indicated that they would consider chorionic villi sampling, 20% would not, and 35% were undecided. Respondents were asked to consider separately a series of nine factors and to indicate how each factor would influence their choice between amniocentesis or chorionic villi sampling (Table II). The factors that influenced most respondents to choose amniocentesis included the known low-risk of spontaneous abortion or fetal damage and confidence in the physician's skill in performing the procedure. In contrast, the performance of the procedure during the first trimester of pregnancy, the shorter period of waiting for the diagnostic results, and the type of abortion procedure available in the first trimester were the factors that would influence most of the women to choose chorionic villi sampling. Factors that were not important in choosing between chorionic villi sampling and amniocentesis included the d'iscomfort or pain experienced during the procedure, confidence in the accuracy of the test results, and the cost of the procedure. When asked to consider all of the factors together and to indicate which procedure they would choose if faced with the decision, 68% of the respondents chose amniocentesis and 32% chose chorionic villi sampling,
28 McGovern, Goldberg, and Desnick
July, 1986 Am J Obstet Gynecol
Table III. Identification of the critical factors in choosing between amniocentesis or chorionic villi sampling Choice indicated by respondent (% of women) Factor
Amniocentesis
Chorionic villi sampling
Risk of fetal damage Risk of spontaneous abortion Confidence in test results Confidence in the skill of physician Discomfort during procedure Type of abortion available Time of procedure Period of waiting for results
51
8
47
4
41
4
25
7
19 9
0 0 44
9
69
7
II
II
The major factors involved in this decision are summarized in Table III. Respondentswho chose amniocentesis indicated their decision was based on the known low risk of damage to the fetus (51 %) or risk of spontaneous abortion (47%) and confidence in the test results (41 %). The major factors that influenced the respondents to select chorionic villi sampling were the time at which the procedure is done (69%), the type of abortion procedure available (44%), and the shorter waiting period to obtain the results (11 %). Of interest was the finding that most respondents who chose amniocentesis indicated that they would consider (47%) or choose (40%) chorionic villi sampling if the risk of spontaneous abortion resulting from this procedure were shown to be no more than that of amniocentesis. Since the women who participated in this study had previously undergone amniocentesis, it was likely that this experience influenced their attitudes about prenatal diagnosis and the choice between amniocentesis and chorionic villi sampling for a future pregnancy. To determine whether stress and anxiety experienced in the previous prenatal diagnosis significantly affected the choice between the two procedures, a X2 analysis of the data was performed. Among respondents .who reported that amniocentesis was "extremely stressful" there was a statistically significant increase in selecting chorionic villi sampling over respondents who found amniocentesis to be moderately or not at all stressful (0.05 > p> 0.02; a = 0.05). In contrast, those respondents who waited a relatively longer time (>3 weeks) to receive diagnostic results did not preferentially choose chorionic villi sampling when compared to those who had waited a shorted period «3 weeks) for the
test results (0.50 > P > 0.10). Similarly, the educational level bf the respondents (that is, high school versus college versus graduate school) did not significantly influence their choice (0.50> P > 0.10; a = 0.05).
Comment Health care providers have become increasingly aware of patient consumerism and the impact of patient preferences on the use of diagnostic techniques, participation in screening programs, and compliance with treatment regimens. Thus the comparison of the acceptabiiity of chorionic villi sampling versus amniocentesis to women at an increased risk of having a child with a genetic defect is important for estimating the future use of chorionic villi sampling for prenatal diagnosis. In addition, the identification of the critical factors that influence women choosing between chorionic villi sampling and amniocentesis may provide the basis for the further development and improved delivery of both techniques. Therefore a retrospective study of 365 women of advanced maternal age who had previously undergone amniocentesis was conducted to assess the attitudes of potential users toward chorionic villi sampling and to determine its acceptability compared to that of amniocentesis. The demographic characteristics of the participants were similar to those reported for patients seeking prenatal diagnosis at other testing centers in New York City and in other areas of the United States. 12• 15 The concerns of the respondents before undergoing amniocentesis in their most recent pregnancy included fear that the fetus would be harmed, that a spontaneous abortion would occur, or that an abnormality might be discovered. These concerns were similar to those reported by Doherty and Rice l5 for a: population who sought prenatal diagnosis in Rochester, New York. In addition, the respondents reported a high level of anxiety during the period of waiting for diagnostic results after amniocentesis (79% reported moderate to extreme anxiety) and a sense of relief after being informed that the chromosomal studies were normal (99% reported moderate to extreme relief). These findings were similar to those observed by other investigators. 5 . 6 The respondents in the present study also had similar concerns and anxieties before, during, and after amniocentesis and a comparable knowledge of the procedure when compared to participants in previous studies of amniocentesis. 5 .' Thus it was of interest to determine whether these women would choose amniocentesis or chorionic villi sampling for future prenatal diagnoses and to identify the factors that influenced the women in their choice. Most respondents indicated that the time at which the procedure is done, the shorter period of waiting for diagnostic results, and the type of abortion available
Volume 155 Number 1
would make them choose chorionic villi sampling (Table II). In contrast, most respondents indicated that the lower incidence of spontaneous abortion after amniocentesis and their confidence in the obstetrician's skill in performing the procedure would influence them to choose amniocentesis. For 86% of respondents, cost was not an important factor. When all factors were considered together and the women were asked to make a final choice between chorionic villi sampling and amniocentesis, 68% chose amniocentesis. For most respondents this decision was based on the known low risk of spontaneous abortion resulting from amniocentesis and the concern that chorionic villi sampling may in some way harm the fetus (Table III). Of interest was the fact that the majority of respondents whose final choice was amniocentesis indicated that they would consider or choose chorionic villi sampling, provided that the risk of spontaneous abortion resulting from chorionic villi sampling were less or equal to that associated with amniocentesis. For respondents whose final choice was chorionic villi sampling, the major influencing factors included the time at which the procedure was done and the type of abortion procedure available. Of interest was the finding that only 11 % of the women said that the shorter period of waiting for the test results was a factor in their decision to choose chorionic villi sampling. Therefore, despite the fact that numerous studies'-7 have documented the extreme stress that women experience while awaiting for diagnostic results, this did not appear to be a critical factor in selecting chorionic villi sampling rather than amniocentesis. Thus the respondents who chose amniocentesis were most concerned with the safety of the fetus, whereas women who chose chorionic villi sampling were most concerned with the time at which the procedure was done and the type of abortion procedure available. It was possible that the relative concerns of these two groups of women were determined by their ages, with older women more concerned with safeguarding the continuance of the pregnancy or by their past history of spontaneous abortions. However, the two groups did not differ significantly in either of these parameters (average age = 36.91 versus 36.78 and average number of spontaneous abortions = 0.41 versus 0.38 for those who chose amniocentesis and chorionic villi sampling, respectively). Another possible difference between the two groups, which was not assessed in this study, was the prior history of fertility and ease of conceiving, since women who have experienced fertility problems may be less willing to risk a spontaneous abortion. Since women of advanced maternal age represent the majority of women seeking prenatal diagnosis, the findings of this study provide insight into the relative ac-
Chorionic villi sampling for prenatal diagnosis
29
ceptabilities of chorionic villi sampling and amniocentesis. However, women who are at risk for having a child with a genetic defect and are at a higher risk (for example, when both members of a couple are carriers of a recessive disorder) may be more concerned with the timing of the procedure and the type and safety of the abortion procedure available should they elect to terminate an affected pregnancy. Thus it is likely that the acceptability of chorionic villi sampling to such individuals will be greater than for women in whom advanced maternal age is the only indication. In addition, the availability of chorionic villi sampling and the fact that this method permits termination of an affected pregnancy in the first trimester may result in use of this service by women who in the past have not sought prenatal diagnosis by amniocentesis because of religious and moral objections to second-trimester induced abortion. REFERENCES J. Kazy Z, Rozovsky IS, Bakharev VA_ Chorion biopsy in early pregnancy: a method of early prenatal diagnosis for inherited disorders. Pre nat Diagn 1982;2:39-45. 2. Rodeck CH, Morsmen]M. First trimester chorion biopsy. Br Med Bull 1983;39:338-42. 3. NICHD Study Group, National Registry for Amniocentesis. Midtrimester amniocentesis for prenatal diagnosis. ]AMA 1980;236:1471-6. 4. Simpson NR, Dallaire L, Miller ]R, et al. Prenatal diagnosis of genetic disease in Canada: report of a collaborative study. Can Med Assoc] 1976; 115:739-50. 5. Beeson D, Golbus M. Anxiety engendered by amniocentesis. Birth Defects 1979;15:191-7. 6. Golbus M, Conte F, Schneider E, Epstein G. Intrauterine diagnosis of genetic defects: results, problems, and followup of one hundred cases in a prenatal genetic detection center. AM] OBSTET GY:>iECOL 1974;118:897-905. 7. Rice N, Doherty R. Reflections on prenatal diagnosis: the consumers' views. Soc Work Health Care 1982;8:47-57. 8. Dixson B, Richards T, Reirsch S, Edrich V, Matson M, Jones O. Midtrimester amniocentesis: subjective maternal responses. ] Reprod Med 1981 ;26: 10-6. 9. Blumberg RD, Golbus M, Hanson K. The psychological sequelae of abortion performed for a genetic indication. AM] OBSTET GYNECOL 1975;122:799-808. 10. Niswander K, Patterson R. Psychological reaction to therapeutic abortion. Obstet Gynecol 1967;29:702-6. I I. Peek A, Marcus H. Psychological sequelae of therapeutic interruption of pregnancy. ] Nerv Ment Dis 1966; 143:417-26. 12. Marion ]P, Kassam G, Fernhoff P, et al. Acceptance of amniocentesis by low-income patients in an urban hospital. AM] OBSTET GYNECOL 1980;138:11-5. 13. Lippman-Hand A, Piper M. Prenatal diagnosis for the detection of Down syndrome: why are so few eligible women tested. Prenat Diagn 1981;1:249-57. 14. ]ahiel RI, Hansen H. Utilization of prenatal chromosome diagnosis in New York City, 1969-1979. Underrepresentation of older women and clinic patients. Am] Hum Genet 1980;32:112A. 15. Doherty RA, Rice N. Knowledge, attitudes and acceptance of prenatal diagnosis among women and physicians in the Rochester region. In: Porter LH, Hook FB, eds. New York: Academic Press, Service and education in medical genetics, 1979:120-34.