Factors affecting the decision regarding amniocentesis in women at genetic risk because of age 35 years or older

Prenatal array comparative genomic hybridization in a well-defined cohort of high-risk pregnancies. A 3-year implementation results in a public tertiary academic referral hospital

OBJECTIVE

To find out whether the diagnostic yield of prenatal array comparative genomic hybridization (aCGH) can be improved by targeting preselected high-risk pregnancies.

METHOD

All the in-house arrays ordered by the Fetomaternal Medical Center from February 2016 until December 2018 were retrospectively analyzed. The indications for array analysis included fetal structural abnormalities, increased nuchal translucency ≥3.5 mm and a chromosomal abnormality in a parent or a sibling. Common aneuploidies were excluded.

RESULTS

Diagnostic yield was 15.1% in the entire patient cohort and as high as 20% in fetuses with multiple structural anomalies. The diagnostic yield was lowest in the group with isolated growth retardation. A total of 76 copy number variants (CNVs) were reported from a total of 65 samples, including 16 CNVs associated with a well-described microdeletion/microduplication syndrome, six autosomal trisomies in mosaic form, and three pathogenic single-gene deletions with dominant inheritance and 12 CNVs known to be risk factors for eg developmental delay.

CONCLUSION

The diagnostic yield of aCGH was higher than what has previously been reported in less defined patient cohorts. However, the number of CNVs with unclear correlation to the fetal ultrasound findings was still relatively high. The importance of adequate pre- and posttest counseling must therefore be emphasized.

Prenatal diagnosis tests and women's risk perception: a cross-sectional study

OBJECTIVE

To investigate women's decision to undergo non-invasive and/or invasive tests for prenatal diagnosis depending on the procedure-related risk and the risk of carrying a foetus with Down syndrome (DS). Both risks are rated in terms of numerical relevance and acceptability.

METHOD

A sample of 448 consecutive women with low-risk pregnancies were interviewed to collect social and clinical variables and to determine their perceptions of the risks of invasive procedure-related miscarriage and carrying a foetus with DS. The risks were scored numerically in terms of their relevance and acceptability using a 10-point rating scale.

RESULTS

The factors related to the use of non-invasive tests were age ≥35 years, not being treated at a public service, rating the risk of carrying a foetus with DS as having high numerical relevance and low acceptability, and rating the risk of miscarriage as having high acceptability. These relationships were still present when the use of invasive tests was considered, except in terms of the numerical relevance of the risk of carrying a foetus with DS.

CONCLUSION

Perceived acceptability affects the interpretation of a given risk more than the numerical relevance of the risk.

Clinical experience of unexpected findings in prenatal array testing

AIM

The aim of this study was to evaluate whether unexpected diagnoses (UD) made by prenatal array testing contribute to pregnancy management.

PATIENTS & METHODS

In 2010-2015 in 19/4043 (0.5%) pregnancies an UD was made. The clinical usefulness of UDs was assessed based on the couple's responses during post-test counseling and their decisions.

RESULTS

In 16/19 cases, the UD was helpful either for the couples in making a decision about the course of their pregnancy, for perinatal management or family genetic counseling.

CONCLUSION

The majority of the pregnant couples found the UDs relevant for pregnancy management and genetic counseling. This adds another motive for offering whole genome array during pregnancy in patients who wish broad testing of their fetus.

The limited effect of information on Israeli pregnant women at advanced maternal age who decide to undergo amniocentesis

Background

A primary goal of amniocentesis is the detection of trisomy 21 (Down syndrome- DS) in the fetus. This procedure involves a small risk of miscarriage. As the risk of DS increases with maternal age, screening tests (maternal serum triple test and others) and age are used to generate a risk assessment, and amniocentesis is offered to women with high risk. In Israel, amniocentesis is government funded for women of advanced maternal age (AMA, i.e., ≥35 years), even if their risk assessment is low.

The purpose of this study was to explore the reasons AMA women undergo amniocentesis, their knowledge about risk estimates, and to evaluate whether their decision is informed.

Methods

Shortly after undergoing amniocentesis, 42 consecutive women without a medical indication for amniocentesis other than age, completed a questionnaire that assessed their knowledge and opinions regarding screening tests, pregnancy termination, amniocentesis risks and the factors that affected their decision.

Results

Women rarely deliberated before undergoing amniocentesis. One third of those who had the screening test did not wait for the results before undergoing amniocentesis. Only one third of those who received the screening results remembered their risk estimation before going ahead with amniocentesis. Almost half (41 %) cited “age” as their main reason for undergoing amniocentesis, though only 44 % of these women could recall their age related DS risk. Sixty percent estimated their DS risk as low or very low but still had amniocentesis. Most participants (74 %) stated that they would consider termination of the pregnancy if the fetus was diagnosed with an intellectual deficit.

Conclusions

These results cast doubt on whether AMA women’s decision to undergo amniocentesis is based on risk estimates, as women seem to disregard risk estimates, and sometimes not even wait for them when making the decision. The policy of funding amniocentesis solely on the basis of age may have led to the conception that being over 35 alone is sufficient reason to undergo amniocentesis. This finding should inform policy makers, as it raises questions about the link between public funding and the choices of individual women, and has implications for healthcare expenditures.

A Priori Attitudes Predict Amniocentesis Uptake in Women of Advanced Maternal Age: A Pilot Study

Amniocentesis is an invasive procedure performed during pregnancy to determine, among other things, whether the fetus has Down syndrome. It is often preceded by screening, which gives a probabilistic risk assessment. Thus, ample information is conveyed to women with the goal to inform their decisions. This study examined the factors that predict amniocentesis uptake among pregnant women of advanced maternal age (older than 35 years old at the time of childbirth). Participants filled out a questionnaire regarding risk estimates, demographics, and attitudes on screening and pregnancy termination before their first genetic counseling appointment and were followed up to 24 weeks of gestation. Findings show that women's decisions are not always informed by screening results or having a medical indication. Psychological factors measured at the beginning of pregnancy: amniocentesis risk tolerance, pregnancy termination tolerance, and age risk perception affected amniocentesis uptake. Although most women thought that screening for Down syndrome risk would inform their decision, they later stated other reasons for screening, such as preparing for the possibility of a child with special needs. Findings suggest that women's decisions regarding amniocentesis are driven not only by medical factors, but also by a priori attitudes. The authors believe that these should be addressed in the dialogue on women's informed use of prenatal tests.

Attitudes of women of advanced maternal age undergoing invasive prenatal diagnosis and the impact of genetic counselling

Despite the increasing availability and effectiveness of non-invasive screening for foetal aneuploidies, most women of advanced maternal age (AMA) still opt for invasive tests. A retrospective cross-sectional survey was performed on women of AMA undergoing prenatal invasive procedures, in order to explore their motivations and the outcome of preliminary genetic counselling according to the approach (individual or group) adopted. Of 687 eligible women, 221 (32.2%) participated: 117 had received individual counselling, while 104 had attended group sessions. The two groups did not differ by socio-demographic features. The commonest reported reason to undergo invasive tests was AMA itself (67.4%), while only 10.4% of women mentioned the opportunity of making informed choices. The majority perceived as clear and helpful the information received at counselling, and only 12.7% had doubts left that, however, often concerned non-pertinent issues. The impact of counselling on risk perception and decisions was limited: a minority stated their perceived risk of foetal abnormalities had either increased (6.8%) or reduced (3.6%), and only one eventually declined invasive test. The 52.6% of women expressed a preference toward individual counselling, which also had a stronger impact on perceived risk reduction (P=0.003). Nevertheless, group counselling had a more favourable impact on both clarity of understanding and helpfulness (P=0.0497 and P=0.035, respectively). The idea that AMA represents an absolute indication for invasive tests appears deeply rooted; promotion of non-invasive techniques may require extensive educational efforts targeted to both the general population and health professionals.

Factors that affect the decision to undergo amniocentesis in women with normal Down syndrome screening results: it is all about the age

BACKGROUND

Risk for foetal Down syndrome (DS) increases as maternal age increases. Non-invasive screening (maternal serum triple test) for DS is routinely offered to pregnant women to provide risk estimates and suggest invasive amniocentesis for definitive pre-natal diagnosis to high-risk women.

OBJECTIVE

We examined women's decision process with regard to pre-natal screening, and specifically, the degree to which they take into account triple serum screening results when considering whether or not to undergo amniocentesis.

DESIGN

Semi-structured phone interviews were conducted to assess recall of DS screening results, understanding of risk estimates and their effect on women's decision whether to undergo amniocentesis. The study included 60 pregnant Israeli women (half younger than 35 and half advanced maternal age - AMA), with normal DS screening results and no known ultrasound abnormalities.

RESULTS

Age appeared to determine the decision process. The vast majority of AMA women had amniocentesis, many of them before receiving their DS screening results. Most AMA participants knew that their risk estimate was 'normal', but still considered themselves at high risk due to their age. Procedure-related risk (miscarriage) and other factors only had a minor effect on their decision. A minority of younger women had amniocentesis. Younger women mentioned procedure-related risk and having normal screening results as the main factors affecting their decision not to have amniocentesis.

CONCLUSION

Age 35 is an anchor for the pre-determination regarding performing or avoiding amniocentesis. AMA women mention 'age' as their main reason to have amniocentesis and considered it an independent risk factor.

A systematic review of factors influencing uptake of invasive fetal genetic testing by pregnant women of advanced maternal age

Women of advanced maternal age have a higher risk of having a child affected by a chromosomal disorder than younger childbearing women and are frequently offered invasive testing during pregnancy. The aim of our systematic review was to identify and analyse the current evidence base regarding factors that influence the uptake of invasive fetal testing by pregnant women of advanced maternal age. We conducted a systematic review. A search of The Cochrane Library, CINAHL, Embase and Medline databases was undertaken for papers published in English and Italian from January 2002 to May 2012. Eleven studies satisfied the inclusion criteria, were subjected to quality assessment and included in the review. We analysed the data using thematic analysis. The factors influencing women were classified as either external or psychosocial factors. External factors included the opportunity for screening, screening results and use of genetic counselling. Psychosocial factors related to ethnicity, socio-demographic status and attendance of partners during counselling. It is difficult to draw firm conclusions as to the principle factors that influence uptake of invasive tests by women of AMA. More research is needed to enhance understanding of relevant factors to ensure that services are offered in a way that acknowledges practical as well as psychosocial influences. This type of research will help to equip midwives and other professionals caring for women during pregnancy to ensure that women are supported to make the choices that are appropriate for them and their families.

Factors determining uptake of invasive testing following first-trimester combined testing

OBJECTIVE

This study aims to analyze differences in characteristics between women who opted for invasive testing after first-trimester combined testing and those who did not.

METHOD

Follow-up was performed in 20 215 combined tests conducted between 2007 and 2011 in the central region of the Netherlands. Multivariate logistic regression analysis compared variables (Down syndrome risk estimate, maternal age, previous Down syndrome pregnancy, IVF/ICSI, parity and nuchal translucency measurement) between different groups.

RESULTS

65.4% of women with a Down syndrome risk estimate ≥1 in 200 opted for invasive 49 testing. In a multivariate model, women opting for invasive testing were significantly younger (odds ratio 0.92; 95% confidence interval 0.88-0.95) and less likely to have had IVF/ICSI (odds ratio 0.57; 95% confidence interval 0.37-0.87) than women opting out on invasive testing. In this high risk group, women <36 years opted for invasive testing more frequently, regardless of their Down syndrome risk estimate magnitude. Women ≥36 years let the magnitude of the risk estimate count significantly in their decision to opt for invasive testing.

CONCLUSION

Because of the dissimilarity in the offer of prenatal screening and invasive diagnosis in the Dutch prenatal screening policy, women <36 years and women >36 years make different choices when confronted with similar Down syndrome risk estimates.

Using Comparison Scenarios to Improve Prenatal Risk Communication

The present research provides empirical evidence of whether communicating the prenatal risk of chromosomal anomalies using comparison scenarios influences women’s ability to distinguish between different risk levels. In 2 experiments, participants read a description of a hypothetical woman who was learning of the risk of chromosomal anomaly as a result of a prenatal screening test. Both experiments used a 3 (risk level) × 3 (scenario) full between-subjects design. In accordance with the experimental condition, participants were presented with a low (e.g., 1 in 5390), a medium (e.g., 1 in 770), or a high risk value (e.g., 1 in 110). Such risk values were presented either on their own or along with additional information illustrating a comparison scenario that provided 2 numerical comparison points. Participants were asked to evaluate the risk of chromosomal anomaly. In Experiment 2, participants’ numeracy skills were also assessed. Results showed that the use of comparison scenarios results in significant differences in perceived risk across risk levels whereas such differences are not significant without the comparison scenario, but such a technique has differential effects according to participants’ capacity to deal with numbers. Although the technique is beneficial for high-numerate participants, it has no effect on low-numerate participants.

Prenatal genetic testing: an investigation of determining factors affecting the decision-making process

Despite the increase in popularity of prenatal genetic testing, relatively little is known about the role psychological factors play in the decision-making process. In this analogue study, a sample of Italian female university students was used to investigate determining factors that predict the intention of undergoing prenatal genetic testing. Structural Equation Modelling was used to describe the dynamic interplay between knowledge, beliefs, attitudes and health-related behaviour such as prenatal genetic testing. Following the Theory of Reasoned Action, three dimensions predicted the intention to undergo prenatal genetic testing: the need for more scientific information, a positive attitude towards genetic testing, and the inclination to terminate pregnancy after receiving a positive test result. Results showed that less religious women tended to be more in favour of prenatal tests and in undertaking such tests. This preliminary study provides genetic counsellors and policy makers with a clearer picture of their clients' motives and attitudes behind the decision-making process of prenatal genetic testing, contributing to improving both the communication process between counsellors and their clients and the organization of genetic services.

Exploring the role of religiosity and spirituality in amniocentesis decision-making among Latinas

Given the complex array of emotional and medical issues that may arise when making a decision about amniocentesis, women may find that their spiritual and/or religious beliefs can comfort and assist their decision-making process. Prior research has suggested that Latinas' spiritual and/or religious beliefs directly influence their amniocentesis decision. A more intimate look into whether Latinas utilize their beliefs during amniocentesis decision-making may provide an opportunity to better understand their experience. The overall goal of this study was to describe the role structured religion and spirituality plays in Latinas' daily lives and to evaluate how religiosity and spirituality influences health care decisions, specifically in prenatal diagnosis. Semi-structured interviews were conducted with eleven women who were invited to describe their religious beliefs and thoughts while considering the option of amniocentesis. All participants acknowledged the influence of religious and/or spiritual beliefs in their everyday lives. Although the women sought comfort and found validation in their beliefs and in their faith in God's will during their amniocentesis decision-making process, results suggest the risk of procedure-related complications played more of a concrete role than their beliefs.

Difficulties in establishing routine amniocentesis for preterm labor evaluation

After a recent practice change implementing amniocentesis into the evaluation of preterm labor (PTL) or preterm premature rupture of membranes (PPROM), actual performance of the procedure was tracked. Fifty-nine patients were admitted with these diagnoses. Twenty-three patients (39%) were offered amniocentesis and 36 patients (61%) were not offered amniocentesis as part of the clinical protocol. Seven (30%) patients of those offered an amniocentesis underwent the procedure. The predominant reasons for not performing an amniocentesis were patient refusal and provider discomfort. In conclusion, implementation of amniocentesis to evaluate for subclinical infection/inflammation in the setting of PTL or PPROM proved difficult, as only 7 of 59 (11.9%) patients admitted with these diagnoses actually received an amniocentesis.

Trends in prenatal screening and diagnostic testing among women referred for advanced maternal age

OBJECTIVE

We evaluated the trends in uptake of amniocentesis and chorionic villi sampling (CVS) for prenatal diagnosis compared with uptake of first and second trimester prenatal serum screening for Down syndrome among patients referred for genetic counseling for advanced maternal age (AMA).

METHODS

Patients referred for AMA genetic counseling from 2001 through 2008 were informed of both prenatal serum screening and invasive diagnostic testing options. Testing offered and testing decisions were entered in a computer database and uptake rates calculated for each year with trends compared using logistic regression analysis.

RESULTS

From 2001 through 2007, we observed a decline in amniocentesis and CVS uptake (p = 0.0001). This trend reversed in 2008 for both invasive procedures (p = 0.0001). Uptake of prenatal serum screening increased over the study period with uptake of first trimester screening increasing 1.7 fold in 2008.

CONCLUSION

Improved prenatal screening tests and increased availability of screening for AMA patients has led to a steady decline in uptake of invasive testing from 2001 through 2007. This trend reversed from 2007 through 2008. Possible reasons for this reversal are discussed.

Ambivalence toward undergoing invasive prenatal testing: an exploration of its origins

OBJECTIVE

This study explores ambivalence toward undergoing amniocentesis among pregnant women with overall positive attitudes. Its novelty lies in the characterization of the type and origins of the ambivalence.

METHOD

Thirty-six women between 35 and 44 years of age were recruited from a US prenatal testing center to participate in structured telephone interviews.

RESULTS

Thirty women chose to undergo testing. Attitudes toward undergoing amniocentesis were generally positive, although all participants simultaneously described feeling ambivalent. The women desired the information that amniocentesis could provide yet did not want to place their fetus at risk. Participants cited religious, moral, ethical and intellectual values important in shaping their attitudes toward undergoing amniocentesis. Important referents such as partners, other pregnant women, family members and physicians influenced their decisions.

CONCLUSION

Tensions were evident among the intellectual, moral and spiritual values that contribute to ambivalence toward undergoing amniocentesis. Illuminating and discussing such tensions during the genetic counseling sessions prior to testing may resolve some of this ambivalence and thereby increase the quality of decisions women make.

Low uptake of prenatal diagnosis after established carrier status of a balanced structural chromosome abnormality in couples with recurrent miscarriage

OBJECTIVE

To evaluate to what extent couples carrying a balanced structural chromosome abnormality follow up the advice to opt for invasive prenatal diagnosis (PND) in subsequent pregnancies.

DESIGN

Index-control study.

SETTING

Six centers for Clinical Genetics in The Netherlands.

PATIENT(S)

Couples referred for chromosome analysis after recurrent miscarriage between 1992 and 2001 and with at least one pregnancy after disclosure; 239 carrier couples and 389 noncarrier couples.

INTERVENTION(S)

Questionnaire, medical record checking.

MAIN OUTCOME MEASURE(S)

Uptake of invasive PND.

RESULT(S)

Only 53 of 239 (22%) carrier couples underwent a PND procedure (CVS or amniocentesis) in all subsequent pregnancies. A relatively high number, 105 (44%) carrier couples, refrained from PND in all subsequent pregnancies. More carrier couples with maternal age >or=36 years (20/33 = 61%) refrained from PND, compared with carrier couples with maternal age <36 years (85/206 = 41%). In women >or=36 years, an equal proportion of carrier and noncarrier couples refrained from PND (61% vs. 54%).

CONCLUSION(S)

The advice to opt for invasive PND in carrier couples is poorly followed, especially in carrier couples with maternal age >or=36 years. The motivations of carrier couples to opt for or refrain from invasive PND procedures should be the topic for further research to optimize clinical care and informative decision making.

Awareness and attitudes regarding prenatal testing among Texas women of childbearing age

Despite increased visibility and availability of prenatal testing procedures, very little is known about the attitudes among the populace toward these procedures. Using a computer assisted telephone interview of pregnant and non-pregnant women of childbearing age we analyze awareness and attitudes regarding prenatal tests among a diverse group of women of childbearing age in Texas. We also examine maternal characteristics associated with awareness and the willingness to undergo these procedures. While 89% were aware that such tests are available, younger, black and less educated women were less likely to know about prenatal tests for birth defects. Seventy-two percent of respondents said they would want their baby tested while Hispanic and black women were significantly more likely to express an interest than non-Hispanic whites. This study demonstrates the variability of knowledge and beliefs and confirms the importance of taking time to understand an individual's personal beliefs, knowledge and attitudes about prenatal diagnosis.

Normal obstetric ultrasound reduces the risk of Down syndrome in fetuses of older mothers

The objective of this study is to determine whether a normal fetal morphology ultrasound scan in women older than 35 years reduces the risk of aneuploidy. We reviewed the results of amniocentesis and second trimester sonogram in all women older than 35 years from 1991 to 1995. None had prior screening. We excluded fetuses with structural anomalies. We determined the sensitivity and specificity of minor markers in detecting Down syndrome and also determined the reduction in risk of a normal sonogram. Among the 2060 women older than 35 years giving birth during the study period, 16 (0.78%) delivered an infant with Down syndrome. Of the 16 fetuses, two had no prenatal testing or ultrasound, two had invasive testing but no second trimester sonogram, five had a normal sonogram and seven had one or more sonographic markers of Down syndrome. At least 17% of women older than 35 years did not participate in prenatal testing or ultrasound. Ultrasound detected Down syndrome with a sensitivity of 59% (95% confidence interval: 45-72%), a false-positive rate of 10.6% (9.4-11.8%) and a positive predictor value of 1 in 9. The likelihood of having normal karyotype if the sonogram was normal was 0.46 (0.31-0.61). In women older than 35 years, a normal second trimester sonogram reduces the risk of Down syndrome by more than 50%. At least 17% of women older than 35 years do not participate in prenatal testing or ultrasound.

The influence of risk estimates obtained from maternal serum screening on amniocentesis rates

OBJECTIVE

To investigate the influence of Down syndrome risk estimates obtained from maternal serum screening (MSS) on women's choices regarding amniocentesis.

METHODS

Women who screened positive for Down syndrome by an Ontario MSS program between 1993 and 1998 were grouped on the basis of their risk estimate and ethnicity. Amniocentesis uptake rates between the groups were compared in order to determine how the MSS risk estimate influenced uptake.

RESULTS

Analysis of 16 792 women showed that amniocentesis uptake rates increased as the estimated risk increased. Uptake in women < or = 35 was higher than that for older women (70% vs 60%, p = 0.001). Uptake in Caucasian and Asian women was higher than the uptake in Black women (67% vs 49%, p = 0.001). Women aged 35 years or older were more likely to proceed with amniocentesis if the MSS risk estimate was higher than their age-specific risk.

CONCLUSION

The increase in amniocentesis rate paralleled the increase in MSS risk estimate for Down syndrome. Risk-specific amniocentesis rates are higher in women aged less than 35 years. Women aged 35 years or older whose risk estimate by MSS is lower than their age-specific risk are less likely to opt for amniocentesis.

The role of genetic counseling on decisions of pregnant women aged 35 years or over regarding amniocentesis in Turkey

We investigated the effects of genetic counseling given before amniocentesis that is given based on maternal serum screening (using the cut-off value of 1/250) and genetic sonogram results (+/- abnormal ultrasound marker) on pregnant women who are 35 years and older age. Their attitudes towards amniocentesis after genetic counseling were evaluated. Among 340 women, 223 (65.6%) were in the high-risk group and 117 (34.4%) were in the low-risk group according to non-invasive test results. After counseling, 216 pregnant women (167 cases have high-risk, 49 cases who had low-risk) decided to have amniocentesis while 124 women (56 with high-risk and 68 with low-risk) declined it. Fourteen abnormal karyotypes were detected. All pregnant women who had fetuses with chromosomal aberrations were in high-risk group. Our study shows that screening by non-invasive prenatal diagnostic tool has an effect on families' choice of amniocentesis. The use of these test results during counseling decreased the number of amniocentesis in a ratio of 36.5%.

Psychological responses to prenatal NTS counseling and the uptake of invasive testing in women of advanced maternal age

This study examines women's psychological responses to prenatal group genetic counseling, and to subsequent individualized risk counseling. All women (N=123) aged 35 and older underwent nuchal translucency screening (NTS), a prenatal ultrasound screening test. After group counseling, decisional conflict decreased significantly among those reporting at baseline having made a decision about invasive testing (t(222)=2.0, P=0.014) and for those who were uncertain (t(222)=5.74, P <0.0005). After receiving NT-adjusted risks, decisional conflict decreased further for those uncertain about testing at baseline (t(222)=4.64, P <0.0005). There was no change in risk perception and anxiety after group counseling. After NT-adjusted risks were communicated, risk perception decreased significantly (t(230)=5.02, P <0.0005), as did anxiety (t(115)=7.91, P <0.005). Despite reassuring NTS results, the uptake rate for prenatal invasive testing was 78.4%. Risk perception, anxiety, and decisional conflict decreased after individual counseling for reassuring NTS results, but the uptake of invasive testing remained high.

Different preferences for prenatal diagnosis in pregnancies following assisted reproduction versus spontaneous conception

The uptake of prenatal diagnosis in 436 singleton and 146 twin pregnancies following assisted reproduction was compared with a matched group of spontaneous conceptions. The first and second trimester ultrasound examination included target fetal anatomic evaluation and screening by specific markers described for fetal aneuploidy. Women with assisted conception attended significantly more often for first trimester prenatal diagnosis (57.9 versus 34.9%, P < 0.01), but had fewer examinations in the early second trimester at 15-18 weeks (37.8 versus 48.8%, P < 0.01) than those with spontaneous conception. Screen positive results of 6.5 and 6.9% for first trimester examination and 6.0 and 7.3% for second trimester examination were found in assisted conceptions and controls respectively. A significantly higher rate of invasive prenatal diagnosis was observed in the second trimester for spontaneous conceptions, 20.0 versus 11.8% (P < 0.01) compared with assisted conceptions. This was attributed to the higher rate of invasive procedures in advanced maternal age >/=35 years of 40.7 versus 28.6% (P = 0.01) in spontaneous and assisted conceptions respectively. With the purpose of avoiding invasive testing, women with assisted conception were more likely to use the results of the ultrasound examination to guide their final decision about invasive testing, rather than undergo genetic amniocentesis as a first option.

Chorionic villus sampling and amniocentesis: what are the risks in current practice?

PURPOSE OF REVIEW

Public demand for genetic counselling and prenatal diagnosis has increased during the past decade. As invasive diagnostic methods, such as chorionic villus sampling and amniocentesis, still have an important role to play in evaluating the fetus, one of the most important questions to address during genetic counselling is the procedure-related risk of these techniques.

RECENT FINDINGS

The possible factors modifying the specific risk of the actual fetus are discussed, together with factors that have an impact on procedure-related fetal loss and other complications. Risk factors regarding twin pregnancies, first and second-trimester chorionic villus sampling, early and mid-trimester amniocentesis are discussed separately. New developments have recently occurred in the laboratory techniques used in prenatal diagnosis. Their impact on genetic counselling and the employment of invasive techniques are also addressed.

SUMMARY

During genetic counselling, an individually tailored risk assessment needs to be established before any invasive procedure. This should take into account all the factors modifying the specific risk for aneuploidy or other disorders of the fetus, as well as the actual procedure-related risks.