https://www.22qsociety.org/downloads/22q11DS_Guidelines_Epublished_JPeds_May12th2011.pdf

Practical Guidelines for Managing Patients with 22q11.2 Deletion Syndrome

This study examines trends and geographical differences in total and live birth prevalence of trisomies 21, 18 and 13 with regard to increasing maternal age and prenatal diagnosis in Europe. Twenty-one population-based EUROCAT registries covering 6.1 million births between 1990 and 2009 participated. Trisomy cases included live births, fetal deaths from 20 weeks gestational age and terminations of pregnancy for fetal anomaly. We present correction to 20 weeks gestational age (ie, correcting early terminations for the probability of fetal survival to 20 weeks) to allow for artefactual screening-related differences in total prevalence. Poisson regression was used. The proportion of births in the population to mothers aged 35+ years in the participating registries increased from 13% in 1990 to 19% in 2009. Total prevalence per 10 000 births was 22.0 (95% CI 21.7–22.4) for trisomy 21, 5.0 (95% CI 4.8–5.1) for trisomy 18 and 2.0 (95% CI 1.9–2.2) for trisomy 13; live birth prevalence was 11.2 (95% CI 10.9–11.5) for trisomy 21, 1.04 (95% CI 0.96–1.12) for trisomy 18 and 0.48 (95% CI 0.43–0.54) for trisomy 13. There was an increase in total and total corrected prevalence of all three trisomies over time, mainly explained by increasing maternal age. Live birth prevalence remained stable over time. For trisomy 21, there was a three-fold variation in live birth prevalence between countries. The rise in maternal age has led to an increase in the number of trisomy-affected pregnancies in Europe. Live birth prevalence has remained stable overall. Differences in prenatal screening and termination between countries lead to wide variation in live birth prevalence.

/pdf/twenty-year-trends-in-the-prevalence-of-down-syndrome-and-1nv894369m.pdf

Twenty-year trends in the prevalence of Down syndrome and other trisomies in Europe: impact of maternal age and prenatal screening

Objective
The objective of this study was to review the published literature on pregnancy termination following a prenatal diagnosis of Down syndrome in the United States

Method
A systematic search of US English-language articles (1995–2011) was conducted to identify primary research studies that reported data for pregnancies with definitive prenatal diagnosis of Down syndrome with subsequent pregnancy termination Studies that provided indirect estimates of pregnancy termination, such as mathematical models, were excluded The weighted mean termination rate was calculated across studies

Results
Twenty-four studies were accepted The weighted mean termination rate was 67% (range: 61%–93%) among seven population-based studies, 85% (range: 60%–90%) among nine hospital-based studies, and 50% (range: 0%–100%) among eight anomaly-based studies Evidence suggests that termination rates have decreased in recent years Termination rates also varied with maternal age, gestational age, and maternal race/ethnicity

Conclusion
This systematic review presents the largest synthesis of United States data on termination rates following a prenatal diagnosis of Down syndrome Evidence suggests that termination rates are lower than noted in a previous review that was based on less contemporary studies and had an international focus Heterogeneity across studies suggests that a summary termination rate may not be applicable to the entire US population © 2012 John Wiley & Sons, Ltd

https://obgyn.onlinelibrary.wiley.com/doi/pdf/10.1002/pd.2910

Prenatal diagnosis of Down syndrome: a systematic review of termination rates (1995-2011).

During the past few decades age at death for individuals with Down syndrome (DS) has increased dramatically. The birth frequency of infants with DS has long been constant in Sweden. Thus, the prevalence of DS in the population is increasing. The aim of the present study was to analyze mortality and causes of death in individuals with DS during the period 1969-2003. All individuals with DS that died between 1969 and 2003 in Sweden, and all individuals born with DS in Sweden between 1974 and 2003 were included. Data were obtained from the Swedish Medical Birth Register, the Swedish Birth Defects Register, and the National Cause of Death Register. Median age at death has increased by 1.8 years per year. The main cause of death was pneumonia. Death from congenital heart defects decreased. Death from atherosclerosis was rare but more frequent than reported previously. Dementia was not reported in any subjects with DS before 40 years of age, but was a main or contributing cause of death in 30% of the older subjects. Except for childhood leukemia, cancer as a cause of death was rare in all age groups. Mortality in DS, particularly infant mortality, has decreased markedly during the past decades. Median age at death is increasing and is now almost 60 years. Death from cancer is rare in DS, but death from dementia is common.

Changes in mortality and causes of death in the Swedish Down syndrome population.

BACKGROUND—The prevalence of esophageal atresia (EA) has been shown to vary across
different geographical settings. Investigation of geographical differences may provide an insight
into the underlying etiology of EA.
METHODS—The study population comprised infants diagnosed with EA during 1998 to 2007
from 18 of the 46 birth defects surveillance programs, members of the International Clearinghouse
for Birth Defects Surveillance and Research. Total prevalence per 10,000 births for EA was
defined as the total number of cases in live births, stillbirths, and elective termination of pregnancy
for fetal anomaly (ETOPFA) divided by the total number of all births in the population.
RESULTS—Among the participating programs, a total of 2943 cases of EA were diagnosed with
an average prevalence of 2.44 (95% confidence interval [CI], 2.35–2.53) per 10,000 births,
ranging between 1.77 and 3.68 per 10,000 births. Of all infants diagnosed with EA, 2761 (93.8%)
were live births, 82 (2.8%) stillbirths, 89 (3.0%) ETOPFA, and 11 (0.4%) had unknown outcomes.
The majority of cases (2020, 68.6%), had a reported EA with fistula, 749 (25.5%) were without
fistula, and 174 (5.9%) were registered with an unspecified code.
CONCLUSIONS—On average, EA affected 1 in 4099 births (95% CI, 1 in 3954–4251 births)
with prevalence varying across different geographical settings, but relatively consistent over time
and comparable between surveillance programs. Findings suggest that differences in the
prevalence observed among programs are likely to be attributable to variability in population
ethnic compositions or issues in reporting or registration procedures of EA, rather than a real risk
occurrence difference.

/pdf/prevalence-of-esophageal-atresia-among-18-international-2h9c68veb1.pdf

Prevalence of esophageal atresia among 18 international birth defects surveillance programs

BACKGROUND: The aim of this study was to examine trends of Down syndrome (DS) in relation to maternal age and termination of pregnancies (ToP) in 20 registries of the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR) METHODS: Trends of births with DS (live-born and stillborn), ToP with DS, and maternal age (percentage of mothers older than 35 years) were examined by year over a 12-year period (1993-2004) The total mean number of births covered was 1550,000 annually RESULTS: The mean percentage of mothers older than 35 years of age increased from 109% in 1993 to 188% in 2004 However, a variation among the different registers from 4-8% to 20-25% of mothers >35 years of age was found The total mean prevalence of DS (still births, live births, and ToP) increased from 131 to 182/10,000 births between 1993 and 2004 The total mean prevalence of DS births remained stable at 83/10,000 births, balanced by a great increase of ToP In the registers from France, Italy, and the Czech Republic, a decrease of DS births and a great increase of ToP was observed The number of DS births remained high or even increased in Canada Alberta, and Norway during the study period CONCLUSIONS: Although an increase in older mothers was observed in most registers, the prevalence of DS births remained stable in most registers as a result of increasing use of prenatal diagnostic procedures and ToP with DS

Caroline Bower

Papers

International trends of Down syndrome 1993-2004: Births in relation to maternal age and terminations of pregnancies.