Factors affecting parental decisions to terminate pregnancy in the presence of chromosome abnormalities: a Japanese multicenter study

Prenatal diagnosis, pregnancy determination and follow up of sex chromosome aneuploidy screened by non-invasive prenatal testing from 122 453 unselected singleton pregnancies: A retrospective analysis of 7-year experience

The phenotype of SCA patients are diversities, make prenatal counseling and parental decision-making following the prenatal diagnosis of SCA more complicated and challenging. NIPT has higher sensitivity and specificity in screening trisomy 21 syndrome, but the effectiveness of NIPT in detecting SCA is still controversial. This study is a large-scale retrospective cohort of positive SCA screened from unselected singleton pregnancies by non-invasive prenatal testing (NIPT) from a single prenatal center of a tertiary hospital. Clinical information, indications, diagnostic results, ultrasound findings, pregnancy determinations, and follow-up were reviewed and analyzed. 596 cases of SCA positive were screened out of 122 453, giving a positive detection rate of 0.49%. 510 cases (85.6%) conducted with amniocentesis to detect fetal chromosome, of which 236 were confirmed as true positive of SCA with PPV of 46.3% (236/510). Of the 236 cases confirmed as true positive SCA, 114 cases (48.3%)chose to terminate the pregnancy (93.0%, 65.3%, 15.4% and 10.9% for 45,X, 47,XXY, 47,XXX and 47,XYY, respectively), 122 cases (51.7%) elected to continue the pregnancy. In conclusions, NIPT as a first-tier routine method for screening autosomal aneuploidies, also could play an important role in screening SCA. Low-risk pregnant women are the main indication for the detection of SCA as NIPT test provides to non-selective population. For 47,XXX and 47,XYY with mild phenotype, couples would like to continue the pregnancy. But for 45,X and 47,XXY, parents apt to terminate pregnancy no matter ultrasound abnormalities were found or not.

Conducta médica frente al diagnóstico prenatal de trisomía 18: ¿se aproxima un cambio de paradigma?

El objetivo del trabajo es analizar dos conductas médicas opuestas en la vida prenatal de los niños con trisomía 18: el aborto y los cuidados paliativos perinatales. Se realizó una búsqueda bibliográfica en PubMed a partir de los términos “trisomy 18”, “abortion” y “palliative care”. Actualmente, están cambiando las conductas médicas dirigidas a los niños nacidos con trisomía 18, debido a que ya no se la considera una enfermedad incompatible con la vida. Este cambio de paradigma en la conducta médica posnatal debería reflejarse en la conducta prenatal, para ofrecer a los padres alternativas distintas al aborto. Los cuidados paliativos fetales y perinatales constituyen una respuesta ética válida para el tratamiento de niños con trisomía 18.

Down syndrome live births following assisted reproductive technology in Japan: a nationwide survey between 2007 and 2016

PURPOSE

The use of assisted reproductive technology (ART) and prenatal genetic testing have become more widespread in line with an increase in maternal age. However, the effect of the introduction of non-invasive prenatal testing (NIPT) in April 2013 on pregnancy outcomes in Japan, including the prevalence of Down syndrome live births following ART, has not been investigated. This study aimed to evaluate the trends in the prevalence of Down syndrome live births following ART in Japan.

METHODS

This population-based retrospective study used the Japanese nationwide ART registry. All clinical pregnancies resulting in live births, stillbirths, and termination of pregnancy (TOP) following ART from 2007 to 2016 were included. Pregnancy outcomes involving infants with Down syndrome were evaluated.

RESULTS

Among 351,808 pregnancies, the proportion of mothers with advanced age increased significantly from 2007 to 2016 (from 49.5 to 62.4% and 8.9 to 17.8% for mothers aged ≥ 35 and ≥ 40 years, respectively). The proportion of live births with Down syndrome was 77.3% in 2007, which remained consistent until 2012, but then decreased significantly to 45.1% after 2013 (P < 0.001). The prevalence of Down syndrome live births increased up to 2012 (19.5/10,000 live births), decreased significantly in 2013 (12.1/10,000 live births), and then remained almost stable (11.1-14.7/10,000 live births).

CONCLUSION

The introduction of NIPT balanced the prevalence of Down syndrome live births following ART with recent increasing maternal age in Japan.

Cell-Free DNA Screening for Sex Chromosome Abnormalities and Pregnancy Outcomes, 2018-2020: A Retrospective Analysis

To evaluate the efficacy of non-invasive prenatal screening (NIPT) for detecting fetal sex chromosome abnormalities, a total of 639 women carrying sex chromosome abnormalities were selected from 222,107 pregnant women who participated in free NIPT from April 2018 to December 2020. The clinical data, prenatal diagnosis results, and follow-up pregnancy outcomes of participants were collected. The positive predictive value (PPV) was used to analyze the performance of NIPT. Around 235 cases were confirmed with sex chromosome abnormalities, including 229 cases with sex chromosome aneuploidy (45, X (n = 37), 47, XXX (n = 37), 47, XXY (n = 110), 47, XYY (n = 42)) and 6 cases with structural abnormalities. The total incidence rate was 0.11% (235/222,107). The PPV of NIPT was 45.37% (235/518). NIPT accuracy for detecting sex chromosome polysomes was higher than that for sex chromosome monomers. The termination of pregnancy rate for fetal diagnosis of 45, X, and 47, XXY was higher than that of 47, XXX, and 47, XYY. The detection rate of fetal sex chromosome abnormalities was higher in 2018–2020 than in 2010–2012 (χ² = 69.708, P < 2.2 × 10⁻¹⁶), indicating that NIPT is greatly efficient to detect fetal sex chromosome abnormalities.

Prenatal diagnosis of significant congenital heart disease and elective termination of pregnancy in Nevada

OBJECTIVE

We investigated the relationship between prenatal detection of significant congenital heart disease and elective termination of pregnancy over time in Nevada.

METHODS

We identified those prenatally or post-natally diagnosed with significant congenital cardiovascular malformations in Nevada with birth dates or estimated delivery dates between July 2012 and June 2021.

RESULTS

We identified 1246. Of 1246, 69 underwent fetal demise, 42 had elective termination, and 1135 were live-born. Of the 1135 live-born, 1090 had prenatal care, of which 718 (66%) overall had a prenatal diagnosis of significant congenital heart disease. However, prenatal detection statistically significantly increased over time from 45 to 82%, p = .00001. Termination of pregnancy averaged 10% of those identified within the legal timeframe, and the rate did not statistically significantly increase with increasing prenatal detection rates, p = .56. Of the 42 undergoing elective termination, 23 (55%) had syndromes or comorbidities vs. 280 (25%) of the 1135 live-births, p = .0003.

CONCLUSIONS

In Nevada, despite a statistically significant increase in prenatal detection of significant congenital heart disease over time, termination of pregnancy rates did not increase. Nevertheless, those undergoing elective termination were more likely to have associated syndromes or comorbidities.

Cost-effectiveness of five prenatal screening strategies for trisomies and other unbalanced chromosomal abnormalities: model-based analysis

OBJECTIVE

To evaluate the cost-effectiveness of five prenatal screening strategies for trisomies (13/18/21) and other unbalanced chromosomal abnormalities (UBCA), following the introduction of cell-free DNA (cfDNA) analysis.

METHODS

A model-based cost-effectiveness analysis was performed to estimate prevalence, safety, screening-program costs and healthcare costs of five different prenatal screening strategies, using a virtual cohort of 652 653 pregnant women in France. Data were derived from the French Biomedicine Agency and published articles. Uncertainty was addressed using one-way sensitivity analysis. The five strategies compared were: (i) cfDNA testing for women with a risk following first-trimester screening of ≥ 1/250; (ii) cfDNA testing for women with a risk of ≥ 1/1000 (currently recommended); (iii) cfDNA testing in the general population (regardless of risk); (iv) invasive testing for women with a risk of ≥ 1/250 (historical strategy); and (v) invasive testing for women with a risk of ≥ 1/1000.

RESULTS

In our virtual population, at similar risk thresholds, cfDNA testing compared with invasive testing was cheaper but less effective. Compared with the historical strategy, cfDNA testing at the ≥ 1/1000 risk threshold was a more expensive strategy that detected 158 additional trisomies, but also 175 fewer other UBCA. Implementation of cfDNA testing in the general population would give an incremental cost-effectiveness ratio of €9 166 689 per additional anomaly detected compared with the historical strategy.

CONCLUSION

Extending cfDNA to lower risk thresholds or even to all pregnancies would detect more trisomies, but at greater expense and with lower detection rate of other UBCA, compared with the historical strategy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Equipoise of recent estimated Down syndrome live births in Japan

To support people with Down syndrome (DS), it is essential to know and predict the number of live births of children with this condition. In this study, we estimated DS live birth rates on the basis of maternal age distribution and numbers of births in the general population, the maternal-age specific chance for a live birth of a child with DS, and the prenatal diagnosis/termination rate. The total number of live births in Japan decreased to less than 1 million in 2016 and the percentage of women aged 35 years old or over giving birth has increased by sixfold. Prenatal genetic testing in Japan has gradually become more widespread, and 20% of all cases of DS were diagnosed prenatally in 2016. Meanwhile, the annual projected number of DS live births has remained steady at around 2,200 (22 per 10,000 births). In 2016, it was estimated that 70% of all DS babies were born to women of advanced maternal age (AMA). Given that Japan is facing a decreasing birth rate and an aging population, adoption of the practice of prenatal genetic testing for AMA has balanced the number of DS births over the last 7 years from 2010.

Nationwide survey of fetal myelomeningocele in Japan: Background for fetal surgery

BACKGROUND

Fetal surgery for myelomeningocele (MMC) has yet not been performed in Japan, and the clinical background of fetal MMC in Japan remains poorly described. We examined the prenatal characteristics and perinatal outcomes of fetal MMC to prepare for the introduction of fetal surgery.

METHODS

A nationwide questionnaire survey was conducted with regard to fetuses with MMC between January 2012 and December 2014 at perinatal centers in Japan.

RESULTS

In 50 tertiary centers, 188 cases of MMC were identified, of which 126 (67%) were isolated cases. Only half of the cases involved referral to tertiary centers with a diagnosis of MMC. The median time point for a prenatal diagnosis was 26 weeks' gestation (range, 12-38 weeks); in 54% of cases the diagnosis occurred after 26 gestational weeks, which is over the limit for fetal surgery for MMC. Furthermore, in 22% of cases the diagnosis was made before 22 gestational weeks, and in three-quarters of these cases termination of pregnancy was selected. No fetal or neonatal deaths were observed in the isolated MMC group. MMC repair, ventriculoperitoneal shunt and clean intermittent catheterization were required after birth in 100%, 73% and 55% of isolated MMC cases, respectively. In total, 96% of the tertiary centers cared for <5 cases of fetal MMC per year.

CONCLUSIONS

Gestational age at MMC diagnosis was late mid-gestation, therefore earlier detection is essential when considering fetal treatment of MMC in Japan. Although the survival rate was excellent, in three-quarters of isolated MMC cases ventriculoperitoneal shunt was required. Early detection and centralization of MMC cases at specialized centers should be considered.

Why do patients decline amniocentesis? Analysis of factors influencing the decision to refuse invasive prenatal testing

Background

In recent years, determination of personalized risk for fetal chromosomal anomalies emerged as an important component of prenatal genetic counseling. Women in whom fetal risk for chromosomal aberrations is elevated are offered further testing. The aim of this study was to identify factors that may influence the decision to refuse invasive prenatal testing aimed at determination of fetal karyotype in a group of patients at increased risk of trisomy 21.

Methods

The analysis included 177 patients with singleton pregnancy, whose personalized risk score for trisomy 21 calculated on the basis of the combined test exceeded 1:300. Diagnostic amniocentesis was performed in 125 patients from this subset, since the remaining 52 women declined invasive prenatal testing. The following factors were analyzed as potential determinants of the decision to refuse amniocentesis: maternal age (≥35 years), gravidity, number of miscarriages in previous pregnancies, educational status, marital status, indications to prenatal testing, gestational age at the time of prenatal testing, personalized risk score for fetal chromosomal aberrations and nuchal translucency (NT) value.

Results

A statistically significant relationship was found between the decision to refuse amniocentesis and the number of previous miscarriages, maternal educational level, NT values and personalized risk score for fetal chromosomal aberrations. Multivariate logistic regression analysis identified primary maternal education and history of more than two miscarriages as independent significant predictors of declining amniocentesis. Women with personalized risk scores for trisomy 21 greater than 1:100 opted out of invasive prenatal diagnosis significantly less often than the remaining participants.

Conclusion

In conclusion, the key role of high quality and accuracy of non-invasive diagnostic tests conducted in the first trimester should be emphasized as personalized risk score for fetal chromosomal aberrations determined based on their results is pivotal for further management of pregnancy. Equally important is to provide the patients with an accurate and comprehensible information about potential benefits and risks of invasive testing.

Sex chromosome aneuploidy detection by noninvasive prenatal testing: helpful or hazardous?

OBJECTIVES

To assess the incidence of sex chromosome aneuploidy (SCA) predicted by noninvasive prenatal testing (NIPT), assess test performance, and compare it with nuchal translucency (NT) screening among patients seen in our prenatal diagnosis center.

METHODS

We identified suspected cases of SCA by reviewing results from all NIPT samples sent from our center to commercial laboratories offering analysis by cell-free DNA between 1 December 2012 and 31 July 2015. Records of pregnancies positive for SCA were reviewed for ultrasound findings, NIPT indications, and karyotype results on maternal, fetal, and postnatal samples. Other SCA cases presenting during this period regardless of NIPT status were identified from genetic counseling and cytogenetics laboratory logbooks.

RESULTS

Noninvasive prenatal testing predicted SCA in 18/2851 patients (0.63%). All had diagnostic testing of fetal or newborn samples. No patients terminated pregnancies on the basis of NIPT. NIPT suggested triple X in five cases, two with elevated NT: all were confirmed on karyotype. Two Klinefelter syndrome cases were also accurately predicted by NIPT. NIPT indicated monosomy X in 11 cases. Only one was a true positive. Ten were false positives, with 46, XX found on fetal or newborn karyotype. Maternal karyotype was mosaic (45, X[4], 46, XX[26]) in one case. Over the same time period, four additional cases of 45, X were confirmed on fetal samples, all with cystic hygromas. One of these had had a false negative NIPT result. The remaining patients pursued only direct testing via CVS or amniocentesis.

CONCLUSIONS

Sex chromosome aneuploidy was frequently suspected on NIPT. False positive rate for monosomy X was surprisingly high (91%). Prediction of other SCA was more accurate. Diagnostic fetal chromosome analysis should be offered after abnormal NIPT or in the presence of cystic hygromas despite normal NIPT. NIPT limitations should be explained in pretest counseling. © 2017 John Wiley & Sons, Ltd.

Current status of non-invasive prenatal testing in Japan

AIM

The purpose of this study was to report the 3-year experience of a nationwide demonstration project to introduce non-invasive prenatal testing (NIPT) of maternal plasma for aneuploidy, and review the current status of NIPT in Japan.

METHODS

Tests were conducted to detect aneuploidy in high-risk pregnant women, and adequate genetic counseling was provided. The clinical data, test results, and pregnancy outcomes were recorded. We discuss the problems of NIPT on the basis of published reports and meta-analyses.

RESULTS

From April 2013 to March 2016, 30 613 tests were conducted at 55 medical sites participating in a multicenter clinical study. Among the 30 613 women tested, 554 were positive (1.81%) and 30 021 were negative (98.1%) for aneuploidy. Of the 289, 128, and 44 women who tested positive for trisomies 21, 18, and 13, respectively, and underwent definitive testing, 279 (96.5%), 106 (82.8%), and 28 (63.6%) were determined to have a true-positive result. For the 13 481 women with negative result and whose progress could be traced, two had a false-negative result (0.02%). The tests were performed on the condition that a standard level of genetic counseling be provided at hospitals.

CONCLUSION

Here, we report on the 3-year nationwide experience with NIPT in Japan. It is important to establish a genetic counseling system to enable women to make informed decisions regarding prenatal testing. Moreover, a welfare system is warranted to support women who decide to give birth to and raise children with chromosomal diseases.