Invasive Prenatal Diagnostic Testing Research Articles

Characteristics and mode of inheritance of pathogenic copy number variants in prenatal diagnosis

Microdeletions and microduplications can occur in any pregnancy independent of maternal age. The spectrum and features of pathogenic copy number variants including the size, genomic distribution, and mode of inheritance are not well studied. These characteristics have important clinical implications regarding expanding noninvasive prenatal screening for microdeletions and microduplications. The aim was to investigate the spectrum and characteristics of pathogenic copy number variants in prenatal genetic diagnosis and to provide recommendations for expanding the scope of noninvasive prenatal screening for microdeletions and microduplications. This was a retrospective study of 1510 pregnant women who underwent invasive prenatal diagnostic testing by chromosomal microarray analysis. Prenatal samples were retrieved by amniocentesis or chorionic villus sampling and sent to our prenatal genetic diagnosis laboratory for chromosomal microarray analysis. The risk of carrying a fetus with pathogenic copy number variants is stratified by the patients' primary indication for invasive testing. We searched the literature for published prenatal chromosomal microarray data to generate a large cohort of 23,865 fetuses. The characteristics and spectrum of pathogenic copy number variants including the type of aberrations (gains or losses), genomic loci, sizes, and the mode of inheritance were studied. Overall, 375 of 23,865 fetuses (1.6%) carried pathogenic copy number variants for any indication for invasive testing, and 44 of them (11.7%) involve 2 or more pathogenic copy number variants. A total of 428 pathogenic copy number variants were detected in these fetuses, of which 280 were deletions and 148 were duplications. Three hundred sixty (84.1%) were less than 5 Mb in size and 68 (15.9%) were between 5 and 10 Mb. The incidence of carrying a pathogenic copy number variant in the high-risk group is 1 in 36 and the low-risk group is 1 in 125. Parental inheritance study results were available for 311 pathogenic copy number variants, 71 (22.8%) were maternally inherited, 36 (11.6%) were paternally inherited, and 204 (65.6%) occurred de novo. Collectively, pathogenic copy number variants are common in pregnancies. High-risk pregnancies should be offered invasive testing with chromosomal microarray analysis for the most comprehensive investigation. Detection limits on size, parental inheritance, and genomic distribution should be carefully considered before implementing copy number variant screening in expanded noninvasive prenatal screening.

How Uncertain Are Patients in Regards to Invasive Prenatal Genetic Diagnostic Testing? [25K

INTRODUCTION: The purpose of this project is to determine patients' decisional certainty regarding the use of invasive prenatal genetic diagnostic testing (PGDT). METHODS: Cross-sectional design, IRB-approved study. Voluntary, anonymous questionnaire (Q) assessing patient decision making process in regards to invasive (CVS and/or amniocentesis) PGDT. Q (paper and online options) were distributed from 2017-2018 to those undergoing genetic testing in a university academic practice. Questions (7 items on certainty, 5-point Likert scale) were structured to evaluate patient decisional certainty, and were partly adapted from published validated Q's. Exclusion criteria: English or Spanish illiterate. Means, variances (SD), and ranges were tabulated. RESULTS: 50 female patients returned the study; 38 (76%) completed it entirely. Patients mean age was 31.76±6.07 years and 79% were Caucasian. 75% had equal PGDT decision making with their partner. Most were referred due to a positive carrier screen, or a positive cell free DNA result. 71% of patients had already made a decision at the time of the Q. Participants expressed high certainty of their decision to do PGDT (mean 3.18 on a 1=uncertain to 5=certain scale, SD 0.79). Non-white women appeared to have greater decisional certainty than white patients (3.54 (SD 0.6) v 3.08 (SD 0.8), respectively). CONCLUSION: Patients are very certain in their decision-making regarding PGNT; however this may be a reflection of when they completed the survey as most did so after deciding on PGDT.

How Well Do Patients Clearly Understand Invasive Prenatal Genetic Diagnostic Testing? [38L

INTRODUCTION: To determine patient clarity of the perceived benefits/drawbacks about invasive prenatal genetic diagnostic testing (PGDT). METHODS: Cross-sectional design. Voluntary, anonymous questionnaire (Q) assessing patient's decision making process in regards to invasive (CVS and/or amniocentesis) PGDT. Qs (paper and online options) were distributed between 2017 and 2018 to those recommended for PGDT in a university academic practice. Questions (5 items on clarity, 5-point Likert scale) were structured to evaluate patient decisional clarity, and were partly adapted from published validated Q's. Exclusion criteria: English or Spanish illiterate. Means, variances (SD), and ranges were tabulated. RESULTS: 50 female patients returned the study; 38 (76%) completed it in entirety. 75% had equal PGDT decision making with their partner. Most were referred due to a positive carrier screen followed by positive cell free DNA result. Participants expressed high clarity of understanding advantages and disadvantages of PGDT (mean 3.28 on a 1=no clarity to 5=high clarity scale, SD 0.94). CONCLUSION: Patients have a clear understanding of PGDT; this may be attributable to in office counseling (MD and/or genetic counselors) done prior to decision making.

Impact of cell-free fetal DNA on invasive prenatal diagnostic tests in a real-world public setting.

Objective To evaluate the impact of cell-free fetal DNA (cfDNA) test on the number of invasive tests carried out in a public hospital that does not include this test in its services. Methods This was a retrospective cohort study in singleton pregnancies with a high risk (>1:270) on the first-trimester screening for aneuploidies. The options of performing an invasive test or a cfDNA test were explained to all women, the latter being especially recommended to those with a 1:50-1:270 risk (Group 1). If the risk was >1:50 (Group 2), or nuchal translucency (NT) was >99th percentile or there were major malformations (Group 3), invasive test was recommended. Results A total of 755 of 14,398 (5.2%) cases had a high-risk first-trimester screening, of whom 46 cases were excluded due to incomplete follow-up. In the remaining 709 cases, the percentage of aneuploidies was 9.9% (70 cases) and 110 opted for a cfDNA test (15.5%). There were two true-positive results of cfDNA (one in Group 2 and another in Group 3). In Group 1, 67.4% [95% confidence interval (CI) 60.0%-72.1%, P < 0.01] fewer invasive procedures were performed in those who opted for a cfDNA test, without having false negatives. Conclusion Pregnant women with a 1:50-1:270 risk who opt for cfDNA save two out of three invasive tests, without affecting the aneuploidy detection rate.

Obstetrical Outcomes of Amniocentesis or Chorionic Villus Sampling in Dichorionic Twin Pregnancies.

BackgroundUnder certain situations, women with twin pregnancies may be counseled to undergo invasive prenatal diagnostic testing. Chorionic villus sampling and amniocentesis are the two generally performed invasive prenatal diagnostic tests. Studies comparing procedure-related fetal loss between first-trimester chorionic villus sampling and second-trimester amniocentesis in twin pregnancies are limited. This study aimed to evaluate the procedure-related fetal loss and the obstetrical outcomes of these two procedures, chorionic villus sampling and amniocentesis in twin pregnancies.MethodsThe data from dichorionic-diamniotic twin pregnancies on which first-trimester chorionic villus sampling (n = 54) or second-trimester amniocentesis (n = 170) was performed between December 2006 and January 2017 in a single center were retrospectively analyzed. The procedure-related fetal loss was classified as loss of one or all fetuses within 4 weeks of procedure, and overall fetal loss was classified as loss of one or all fetuses during the gestation. The groups were compared with respect to the procedure-related and obstetrical outcomes.ResultsThe difference in proportion of procedure-related fetal loss rate (1.9% for chorionic villus sampling vs. 1.8% for amniocentesis; P = 1.000) and the overall fetal loss rate (7.4% for chorionic villus sampling vs. 4.7% for amniocentesis; P = 0.489) between the two groups was not significant. The mean gestational ages at delivery were not statistically significant.ConclusionBoth the overall fetal loss rate and the procedure-related fetal loss rate of chorionic villus sampling and amniocentesis in dichorionic twin pregnancies had no statistical significance. Both procedures can be safely used individually.

Fetal chromosomal anomalies in southeast Serbia - single center cohort retrospective study

Congenital anomalies are the cause of prenatal death in 20-25% of the cases, while 3% of children are born with a malformation of varying size. Many of these anomalies can be detected before birth using different non-invasive and invasive prenatal diagnostic tests. This study was used to determine the distribution of genetic disorders in relation to the age of the mother, the frequency of aberrations and to study the effects and importance of prenatal diagnosis in South Serbia. Prenatal diagnostics was performed at the Pediatric Clinic within the Clinical Center of Nis. This retrospective study included a group of 8830 pregnant women, aged between 18 and 47 years during the period from 2004 to 2017. Amniocentesis was performed between the 16th and 18th week of pregnancy and involved the aspiration of 20 ml of amniotic fluid. Isolated cells were cultured in a medium that stimulates cell growth for 10 days. After cytogenetic processing, the obtained karyotype was analyzed using G-banding techniques. In 8830 samples of amniotic fluid cell cultures, 198 karyotypes with chromosomal aberrations were found - 179 with numerical aberrations and 19 with structural aberrations such as translocations, inversions and deletions. There were 85 karyotypes with autosomal numerical aberrations and 32 karyotypes with sex chromosome numerical aberrations. The most frequent one was trisomy 21 (106 cases). The highest number of autosomal numerical aberrations, 84%, was found in pregnancies where maternal age was above 30 years. Preventive action, advice, education and availability of prenatal diagnosis can lead to a significant reduction in the number of children born with various malformations.

Trends in invasive prenatal diagnostic testing at a single institution.

As diagnostic methodologies evolve, we sought to determine whether invasive testing rates would decline, whether there would be a shift in indications for invasive testing, and whether the diagnostic yield would increase. We conducted a retrospective, observational study from 2006 through 2015. We quantified the number of invasive procedures per year and examined what percentage of these procedures yielded abnormal results. We also examined the indications for testing and determined the trend of these indications during the study period. The number of amniocenteses showed a steady decline (P<.05). The number of CVS procedures has increased and was recently equivalent to amniocentesis. The percentage of abnormal results steadily increased from 11.4% to 27.0% (P<.001). The abnormal aneuploidy screening indication remained constant over time. Advanced maternal age (AMA) as the sole indication substantially declined from 42.3% to 15.52% (P<.001). Testing for a known single gene disorder steadily increased from 3.0% to 9.20% (P=.018). Our study showed a significant decline in the number of amniocenteses, a steady increase in the percentage of abnormal results from invasive testing, and a decline in AMA as the sole indication for invasive testing.

Prenatal diagnosis and socioeconomic status in the non-invasive prenatal testing era: A population-based study.

Advances in technology can bring great benefits to human health, but their implementation may be influenced by socioeconomic factors, particularly in the field of prenatal screening for Down syndrome. To analyse screening test indications for, and diagnostic yield of, invasive prenatal diagnostic testing (PNDx) according to socioeconomic status. Retrospective analysis of population-based data on PNDx and karyotype results for 2014-2015 in the Australian state of Victoria. Women having PNDx<25weeks due to combined first trimester screening (CFTS), second trimester serum screening (STSS), or noninvasive prenatal testing (NIPT) results were included. PNDx data were analysed by indication and maternal Index of Relative Socio-economic Advantage and Disadvantage (IRSAD), the latter determined by postcode. There were 145206 births in 2014-2015; 1906 women underwent PNDx for the indication of CFTS (70.1%), NIPT (17.8%) or STSS (12.0%). Covariates positively associated with NIPT-indicated PNDx, compared with CFTS-indicated testing, were residence in a region of socioeconomic advantage, metropolitan status and maternal age. Women from the most advantaged regions had higher adjusted odds ratios (aOR) of NIPT-indicated testing compared with women from disadvantaged regions (aOR 5.72, 95% CI: 2.95-11.09). The diagnostic yield of PNDx increased with socioeconomic region, from 14% in the lowest IRSAD quintile to 31.2% in the highest (P<0.0001). Population-based data reveal significant disparities in screening indications for PNDx and hence, in diagnostic yield, according to socioeconomic region. This finding may have ethical and policy implications for prenatal screening in Australia.

Clinical Utility of High-Throughput Sequencing for Pregnancies with Ultrasound Anomalies in Southern China

We evaluated the clinical utility of high-throughput sequencing for fetal abnormalities detected with ultrasound examination. This study included pregnant women who were at risk for fetal aneuploidy with or without ultrasonography abnormalities, and who underwent invasive surgery. High-throughput sequencing was used for cell-free fetal DNA analysis, and some positive results were compared with conventional karyotyping. This study involved 971 pregnancies, cell-free fetal DNA identified 15 of 18 (83.33%) as fetal Down syndrome, 4 of 5 (80.00%) as trisomy 18, and 0 of 1 (0.00%) as trisomy 13. Comparing high-throughput sequencing results with conventional fetal karyotypes, we observed that sequencing revealed sub-chromosomal duplications or deletions, but results of karyotyping showed aberrations in chromosome structure or a normal karyotype. One chromosomal balanced translocation was inherited from the mother, another one chromosomal abnormalities was inherited from the father. When fetal chromosomal abnormalities were found by ultrasound abnormalities, non-invasive prenatal testing should not be recommended for the genetic evaluation. Invasive procedure should be first offered to the pregnant woman when abnormal nuchal translucency or other ultrasound abnormalities were found. During invasive prenatal diagnostic testing, fetal chromosomal anomalies should be evaluated by high-throughput sequencing combining with conventional karyotyping.

Successful obstetric and anaesthetic management of a pregnant woman with achondroplasia

Achondroplasia is the most prevalent form of dwarfism, and there is little evidence about the optimal management of pregnant women with achondroplasia. We presented a 25-year-old primigravid woman with achondroplasia...

No. 261-Prenatal Screening for Fetal Aneuploidy in Singleton Pregnancies.

To develop a Canadian consensus document on maternal screening for fetal aneuploidy (e.g., Down syndrome and trisomy 18) in singleton pregnancies. Pregnancy screening for fetal aneuploidy started in the mid 1960s, using maternal age as the screening test. New developments in maternal serum and ultrasound screening have made it possible to offer all pregnant patients a non-invasive screening test to assess their risk of having a fetus with aneuploidy to determine whether invasive prenatal diagnostic testing is necessary. This document reviews the options available for non-invasive screening and makes recommendations for Canadian patients and health care workers. To offer non-invasive screening for fetal aneuploidy (trisomy 13, 18, 21) to all pregnant women. Invasive prenatal diagnosis would be offered to women who screen above a set risk cut-off level on non-invasive screening or to pregnant women whose personal, obstetrical, or family history places them at increased risk. Currently available non-invasive screening options include maternal age combined with one of the following: (1) first trimester screening (nuchal translucency, maternal age, and maternal serum biochemical markers), (2) second trimester serum screening (maternal age and maternal serum biochemical markers), or (3) 2-step integrated screening, which includes first and second trimester serum screening with or without nuchal translucency (integrated prenatal screen, serum integrated prenatal screening, contingent, and sequential). These options are reviewed, and recommendations are made. Studies published between 1982 and 2009 were retrieved through searches of PubMed or Medline and CINAHL and the Cochrane Library, using appropriate controlled vocabulary and key words (aneuploidy, Down syndrome, trisomy, prenatal screening, genetic health risk, genetic health surveillance, prenatal diagnosis). Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. There were no language restrictions. Searches were updated on a regular basis and incorporated in the guideline to August 2010. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment- related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. The previous Society of Obstetricians and Gynaecologists of Canada guidelines regarding prenatal screening were also reviewed in developing this clinical practice guideline. The quality of evidence was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care. This guideline is intended to reduce the number of prenatal invasive procedures done when maternal age is the only indication. This will have the benefit of reducing the numbers of normal pregnancies lost because of complications of invasive procedures. Any screening test has an inherent false- positive rate, which may result in undue anxiety. It is not possible at this time to undertake a detailed cost-benefit analysis of the implementation of this guideline, since this would require health surveillance and research and health resources not presently available; however, these factors need to be evaluated in a prospective approach by provincial and territorial initiatives.

Hepatitis C in pregnancy: screening, treatment, and management

In the United States, 1-2.5% of pregnant women are infected with hepatitis C virus, which carries an approximately 5% risk of transmission from mother to infant. Hepatitis C virus can be transmitted to the infant in utero or during the peripartum period, and infection during pregnancy is associated with increased risk of adverse fetal outcomes, including fetal growth restriction and low birthweight. The purpose of this document is to discuss the current evidence regarding hepatitis C virus in pregnancy and to provide recommendations on screening, treatment, and management of this disease during pregnancy. The following are Society for Maternal-Fetal Medicine recommendations: (1) We recommend that obstetric care providers screen women who are at increased risk for hepatitis C infection by testing for anti-hepatitis C virus antibodies at their first prenatal visit. If initial results are negative, hepatitis C screening should be repeated later in pregnancy in women with persistent or new risk factors for hepatitis C infection (eg, new or ongoing use of injected or intranasal illicit drugs) (GRADE 1B). (2) We recommend that obstetric care providers screen hepatitis C virus-positive pregnant women for other sexually transmitted diseases, including HIV, syphilis, gonorrhea, chlamydia, and hepatitis B virus (GRADE 1B). (3) We suggest that patientswith hepatitis C virus, including pregnant women, be counseled to abstain from alcohol (Best Practice). (4) We recommend that direct-acting antiviral regimens only be used in the setting of a clinical trialor that antiviral treatment be deferred to the postpartum period as direct-acting antiviral regimens are not currently approved for use in pregnancy (GRADE 1C). (5) We suggest that if invasive prenatal diagnostic testing is requested, women be counseled that data on the risk of vertical transmission are reassuring but limited; amniocentesis is recommended over chorionic villus sampling given the lackofdata on the latter (GRADE 2C). (6) We recommend against cesarean delivery solely for the indication ofhepatitis C virus (GRADE 1B). (7) We recommend that obstetric care providers avoid internal fetalmonitoring, prolonged rupture of membranes, and episiotomy in managing labor in hepatitis C virus-positive women (GRADE 1B). (8) We recommend that providers not discourage breast-feeding based on a positive hepatitis C virus infection status (GRADE 1A).

Invasive Prenatal Diagnostic Testing Recommendations are Influenced by Maternal Age, Statistical Misconception and Perceived Liability.

Funding policy and medico-legal climate are part of physicians' reality and might permeate clinical decisions. This study evaluates the influence of maternal age and government funding on obstetrician/gynecologist recommendation for invasive prenatal testing (i.e. amniocentesis) for Down syndrome (DS), and its association with the physician's assessment of the risk of liability for medical malpractice unless they recommend amniocentesis. Israeli physicians (N=171) completed a questionnaire and provided amniocentesis recommendations for women at 18weeks gestation with normal preliminary screening results, identical except aged 28 and 37. Amniocentesis recommendations were reversed for the younger ('yes' regardless of testing results: 6.4%; 'no' regardless of testing results: 31.6%) versus older woman ('yes' regardless of testing results: 40.9%; 'no' regardless of testing results: 7.0%; χ2=71.55, p<.01). About half of the physicians endorsed different recommendations per scenario; of these, 65.6% recommended amniocentesis regardless of testing results for the 37-year-old woman. Physicians routinely performing amniocentesis and those advocating for amniocentesis for all women ≥ age 35 were approximately twice as likely to vary their recommendations per scenario. Physicians who perceived risk of liability for malpractice as large were nearly one-and-a-half times more likely to vary recommendations. The results indicate physicians' recommendations are influenced by maternal age, though age is already incorporated in prenatal DS risk evaluations. The physician's assessment of the risk that they will be sued unless they recommend amniocentesis may contribute to this spurious influence.

Knowledge and attitude changes of pregnant women regarding prenatal screening and diagnostic testsafter counselling

This study aimed to reveal the knowledge level of pregnant women about prenatal diagnostic tests, Down syndrome (DS) and amniocentesis, their attitudes toward uptaking these tests, undergoing amniocentesis, and the termination of pregnancy. It also aimed to evaluate the effects of providing information, as well as a written information brochure about all the issues concerning women's knowledge and attitudes. The gynecologists provided verbal and written information on prenatal screening tests (PSTs) and invasive prenatal diagnostic tests. Data were collected using an anonymous questionnaire, which was designed by the researchers on the basis of the literature. Knowledge of both DS and amniocentesis was found to be significantly higher after the education (p = 0.000 and p = 0.000, respectively). Attitudes toward amniocentesis changed significantly after the education. This study has shown that women had an inadequate knowledge about PSTs, DS, and amniocentesis. It has also revealed that education provided by gynecologists along with a written brochure of information tended to increase women's knowledge about PSTs.

Ethics Case: When is Non - Invasive Prenatal Diagnostic Testing Beneficial?Ethics Case: When is Non - Invasive Prenatal Diagnostic Testing Beneficial?

Ethics Case: When is Non - Invasive Prenatal Diagnostic Testing Beneficial?Ethics Case: When is Non - Invasive Prenatal Diagnostic Testing Beneficial?

Application of chromosomal microarray analysis in prenatal diagnosis of fetal growth restriction.

To investigate the clinical value of chromosomal microarray analysis (CMA) in the prenatal diagnosis of chromosomal abnormalities in fetal growth restriction (FGR) cases. The ultrasound findings of 107 FGR cases subjected to invasive prenatal diagnostic testing from March 2013 to October 2015 were retrospectively reviewed. Karyotyping was performed in all cases, and CMA was performed in 80 cases. In our study, karyotype analysis identified chromosomal aberrations in 9.3% (10/107) of the cases, while CMA detected abnormalities in 18.8% (15/80) of the cases. CMA achieved a 11.4% detection rate of chromosomal abnormalities among FGR cases with a normal karyotype. Among 53 FGR cases without malformations, CMA increased (9.4%; 95%CI, 1.6%-17.3%) the detection rate of chromosomal abnormalities. CMA identified more chromosomal abnormalities (50.0%; 95%CI, 19.0%-81.0%) than karyotyping (30.0%; 95%CI, 7.0%-65.0%) among the cases diagnosed during the second trimester. Further, the detection rate in cases with asymmetric FGR was higher with CMA (33.3%; 95%CI, 10.0%-65.0%) than with karyotyping (16.7 %; 95%CI, 2.0%-48.0%). Our study highlights the added value of CMA compared with karyotyping in evaluation of asymmetric FGR cases diagnosed during the second trimester without sonographic anomalies. © 2016 John Wiley & Sons, Ltd.

Non-invasive prenatal testing: impact on invasive prenatal diagnosis at a mainland Chinese tertiary medical center

Objective: We describe the changes over a 4-year period in the number of diagnostic testing after the introduction of non-invasive prenatal testing (NIPT).Methods: The rate of NIPT as an indication in women who received amniocentesis, and the number of amniocentesis required for detection of one case with major aneuploidy were compared between a 1-year baseline period before the introduction of NIPT, and the 3 years following NIPT introduction.Results: A total of 7536 amniocentesis procedures were performed over the 4-year study period. During the baseline period of the year 2011, the number of invasive testing required for detection of one common trisomy was 57. During the first 2 years that NIPT was offered, NIPT averaged 1.7 percent of the total indications for amniocentesis, and the required number of invasive testing decreased to 30. With the increase of the percentage of NIPT during the 3rd year, the required number of invasive testing further decreased to 26.Conclusion: After the clinical introduction of NIPT, invasive prenatal diagnostic testing had not decreased at a Chinese prenatal diagnostic unit, but a remarkably improved detection rate of major aneuploidies in diagnostic procedures was observed.

464: Trends in invasive prenatal diagnostic testing

464: Trends in invasive prenatal diagnostic testing

Trends in Invasive Prenatal Diagnosis: Effect of Sequential Screening and Noninvasive Prenatal Testing

Objective: To examine trends in the incidence and method of invasive prenatal diagnosis due to the impact of sequential screening and noninvasive prenatal testing. Methods: This is a retrospective review of all pregnancies that have undergone invasive prenatal diagnostic testing between June 2002 and June 2014, divided in 3 periods: period 1 from June 2002 to October 2006, period 2 from November 2006 to December 2011, and period 3 from January 2012 to June 2014. The main outcome measures were trends in the incidence and method of each procedure. Results: There were 88,135 deliveries and 6,080 invasive procedures during the study period. In period 1, 2,755 (8.8%) procedures were carried out, in period 2 2,820 (7.3%), and in period 3 505 (2.5%; p < 0.01). In period 1, there were 1,990 (6.3%) cases of amniocentesis, 1,646 (4.3%) in period 2, and 254 (1.2%) in period 3 (p < 0.01). In addition, in 765 (2.5%) cases, chorionic villus sampling (CVS) was performed in period 1, compared to 1,174 (3.0%) cases in period 2 and 251 (1.3%) cases in period 3 (p < 0.01). Advanced maternal age as the sole indication for invasive procedures decreased significantly over time, while the indication of abnormal serum screening and abnormal ultrasound findings increased (p < 0.01). Conclusion: There was a significant decline in the incidence of invasive prenatal testing over the 12 years of the study. The decrease in amniocentesis was more marked than that in CVS.

British HIV Association guidelines for the management of HIV infection in pregnant women 2012 (2014 interim review).

British HIV Association guidelines for the management of HIV infection in pregnant women 2012 (2014 interim review).