Trends in the use of prenatal diagnosis in New York State and the impact of biochemical screening on the detection of Down syndrome: 1984-1993

Analysis of the Global Disease Burden of Down Syndrome Using YLDs, YLLs, and DALYs Based on the Global Burden of Disease 2019 Data

PURPOSE

This study aimed to determine Down syndrome (DS) burden using years lived with disability (YLDs), years of life lost (YLLs), disability-adjusted life years (DALYs), and the trends in these parameters.

METHODS

We obtained the annual YLDs, YLLs, DALYs, and age-standardized rates (ASRs) of DS from 2010 to 2019 using the Global Health Data Exchange tool. The estimated annual percentage changes (EAPCs) in ASR were used to quantify and evaluate DS burden trends. Gaussian-process regression and Pearson's correlation coefficient were used to assess the relationship between DS burden and socio-demographic index (SDI).

RESULTS

Global DALYs decreased by 2.68% from 2010 to 2019 but the ASR was stable, which was mostly explained by the stability in the ASR for YLLs. The ASR of YLDs showed an increasing trend (EAPC = 1.07, 95% CI = 0.45 to 1.69). There was notable regional imbalance, with most of the DALYs or ASRs in areas with relatively low SDI. The DALY rates of DS were mostly from the YLLs of children younger than 1 year. Lower SDI areas tended to have higher DS burdens (ρ = -0.3, p < 0.001).

CONCLUSION

This systematic analysis of the global disease burden of DS from 2010 to 2019 revealed that although the global DS DALY and YLL rate is stable, the YLD rate is increasing. And the DS burden varies significantly differences among regions or countries. The present results suggest that future strategies should focus on DS-related deaths in children younger than 1 year and the DS burden in low-SDI regions or countries, since this may be effective in further reducing DS burden.

The impact of Down syndrome screening on Taiwanese Down syndrome births: a nationwide retrospective study and a screening result from a single medical centre

A retrospective analysis of the Taiwanese National Birth Defect Registration and Notification System was conducted in order to determine the live birth- and stillbirth rates in infants with Down syndrome, trisomy 18, trisomy 13 and Turner syndrome between 2001 and 2010. The objective was to investigate the impact of Down syndrome screening on the Taiwanese Down syndrome live birth rate. In addition, the results of first-trimester Down syndrome screening between 2006 and 2011, and of second-trimester quadruple testing between 2008 and 2011, were obtained from the National Taiwan University Hospital. All Taiwanese infants born between 2001 and 2010 were included in the first part of the analysis, and women receiving first-trimester Down syndrome screening or second-trimester quadruple testing from the National Taiwan University Hospital were included in the second part. The live birth rate of infants with Down syndrome, per 100 000 live births, decreased from 22.28 in 2001 to 7.79 in 2010. The ratio of liveborn DS to total DS was 48.74% in 2001, and then decreased to 25.88% in 2006, when first-trimester screening was widely introduced in Taiwan. This ratio dropped to 20.64% in 2008, when the second-trimester quadruple test was implemented. The overall positive rate in first-trimester screening in the National Taiwan University Hospital was 3.1%, with a Down syndrome detection rate of 100%; the quadruple test had values of 9.0% and 75%, respectively. The use of first-trimester screening and the second-trimester quadruple test may be responsible for the marked decrease in the Taiwanese Down syndrome live birth rate observed between 2001 and 2010.

Folate gene polymorphisms and the risk of Down syndrome pregnancies in young Italian women

Maternal impairments in folate metabolism and elevated homocysteinemia are known risk factors for having a child with Down syndrome (DS) at a young age. The 80G>A polymorphism of the reduced folate carrier gene (RFC-1) has been recently demonstrated to affect plasma folate and homocysteine levels, alone or in combination with the 677C>T polymorphism in the methylenetetrahydrofolate reductase (MTHFR) gene. We performed the present study on 80 Italian mothers of DS individuals, aged less than 35 at conception, and 111 Italian control mothers, to study the role of the RFC-1 80G>A, MTHFR 677C>T, and MTHFR 1298A>C genotypes to the risk of a DS offspring at a young maternal age. When polymorphisms were considered alone, both allele and genotype frequencies did not significantly differ between DS mothers and control mothers. However, the combined MTHFR677TT/RFC-1 80GG genotype was borderline associated with an increased risk (OR 6 (CI 95%: 1.0-35.9), P = 0.05), and to be MTHF1298AA/RFC-1 80(GA or AA) was inversely associated with the risk (OR 0.36 (CI 95%: 0.14-0.96), P = 0.04). Present results seem to indicate that none of the RFC-1 80G>A, MTHFR 677C>T, and MTHFR 1298A>C polymorphisms is an independent risk factor for a DS offspring at a young maternal age; however, a role for the combined MTHFR/RFC-1 genotypes in the risk of DS pregnancies among young Italian women cannot be excluded.

Abortion attitudes of pregnant women in prenatal care

OBJECTIVE

This study was undertaken to describe abortion attitudes in a diverse cohort of pregnant women enrolled in prenatal care.

STUDY DESIGN

A cross-sectional interview study of 1082 demographically diverse gravid women enrolled in prenatal care at less than 20 weeks' gestation was performed.

RESULTS

Most participants (92%) supported abortion availability. Half (50%) who were willing to consider an abortion would do so only in the first trimester. Among the gravid women willing to consider an abortion in the first or second trimester, 84% would do so after rape/incest or if their life was endangered and 76% would if their fetus had Down syndrome. Gravid women considering abortion were more likely to be white, older, have had a previous abortion, and to express distrust in the health care system. Women who would not consider abortion were more likely to be multiparous, married/living with partner, and to express greater faith and fatalism about their pregnancy outcome.

CONCLUSION

Although most pregnant women enrolled in prenatal care support abortion availability, about half would only consider a first-trimester procedure. These findings underscore the need for early prenatal genetic counseling, screening, and testing.

Comparison of the use of amniocentesis in two countries with different policies for prenatal testing: the case of France and the United States

OBJECTIVE

To compare maternal age- and education-specific use of amniocentesis in France and the United States.

METHODS

We used two nationally representative datasets, National Perinatal Survey of 1998 in France (n = 12 816) and National Center for Health Statistics birth data for 1997 in the United States (n = 3 799 975). Analyses included binomial regression with test of interactions between country, maternal age and education.

RESULTS

Amniocentesis use was more than threefold greater in France than in the United States (Risk Ratio (RR) 3.2, 95% CI, 3.1-3.4). This was true across maternal age and education groups. Differences in use of amniocentesis were greatest, however, for women with lower levels of education and older (>/=38 years) women.

CONCLUSION

Our results suggest greater use and lesser disparities in maternal age- and education-specific use of amniocentesis in France as compared to that in the United States. These differences may be due to several factors, including differences in women's cultural values and preferences. They may also represent barriers to effective access to prenatal testing, particularly for women in lower socioeconomic groups, in the United States.

Down syndrome births in the United States from 1989 to 2001

OBJECTIVE

We investigated the observed and expected Down syndrome livebirths in the US from 1989 to 2001.

STUDY DESIGN

Using birth certificate data, we recorded maternal age-specific live births from 1989 to 2001, and stratified them by women 15 to 34 and 35 to 49 years old. We estimated Down syndrome live births from 1989 to 2001, assuming no terminations. We recorded Down syndrome live births by year from 1989 to 2001.

RESULTS

Despite an expected 1.32-fold increase in Down syndrome live birth rates from 1989 to 2001, Down syndrome live births actually declined. In 1989, the rate of Down syndrome cases was 15% lower than expected, decreasing to 51% by 1998. Women 15 to 34 had 45% fewer affected pregnancies in 2001, while women 35 to 49 had 53% fewer in 2001. We estimated that Down syndrome live births decreased from 3962 in 1989 to 3654 in 2001.

CONCLUSION

Down syndrome live births declined in the US despite an expected increase caused by delayed or extended childbearing.

Down syndrome: progress in research

This review discusses the research published in the last five years on the behavioral, genetic, medical, and neuroscience aspects of Down syndrome. The subject areas that have experienced the most active research include Alzheimer disease, language development, leukemia, and pregnancy screening and diagnosis. These and other areas are reviewed.

The impact of maternal serum screening on the birth prevalence of Down's syndrome and the use of amniocentesis and chorionic villus sampling in South Australia

OBJECTIVES

To describe the impact of maternal serum screening on the birth prevalence of Down's syndrome and on the use of amniocentesis and chorionic villus sampling in South Australia.

DESIGN

A descriptive population-based study.

SETTING

South Australia (population 1.48 million persons; approximately 20,000 births per year).

PARTICIPANTS

Women who had births or terminations of pregnancy with Down's syndrome in 1982-1996, women who had maternal serum screening in 1991-1996, amniocentesis or chorionic villus sampling in 1986-1996.

METHODS

Analysis of data from multiple sources on maternal serum screening, amniocentesis and chorionic villus sampling, births and terminations of pregnancy.

MAIN OUTCOME MEASURES

Total prevalence and birth prevalence of Down's syndrome each year in 1982-1996; proportion of pregnant women using maternal serum screening in 1991-1996, and proportion using amniocentesis and chorionic villus sampling by indication in 1986-1996, by age group.

RESULTS

Use of maternal serum screening for Down's syndrome increased from 17% when introduced in 1991 to 76% of women who gave birth in 1996. Between 1982 and 1986 and 1996, terminations of pregnancy for fetal Down's syndrome increased from 7.1 % to 75% and the birth prevalence of Down's syndrome fell by 60% from 1.05 to 0.42 per 1,000 births, against the background of an increase in total prevalence due to increasing maternal age. The use of amniocentesis increased from 5.8% in 1991 to 10.1% in 1996 mainly due to the increase among women younger than 35 years with maternal serum screening as the main reason. The increasing chorionic villus sampling rate among younger women stabilised at 0.4%, while the rate among older women decreased from 11.0% to 7.4%.

CONCLUSIONS

The introduction of maternal serum screening in South Australia has resulted in increased use of any prenatal testing for Down's syndrome from about 7% (mainly older women having amniocentesis or chorionic villus sampling) to 84% of women (about 8% having direct amniocentesis or chorionic villus sampling and 76% having maternal serum screening first). This has resulted in a significant fall in the birth prevalence of Down's syndrome. maternal serum screening was the first indication of Down's syndrome for about half the terminations of pregnancy for Down's syndrome in 1993-1996, including three quarters of those in younger women.