Premium
Prevalence and risk of D own syndrome in monozygotic and dizygotic multiple pregnancies in E urope: implications for prenatal screening
Author(s) -
Boyle B,
Morris JK,
McConkey R,
Garne E,
Loane M,
Addor MC,
Gatt M,
Haeusler M,
LatosBielenska A,
Lelong N,
McDonnell R,
Mullaney C,
O'Mahony M,
Dolk H
Publication year - 2014
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/1471-0528.12574
Subject(s) - medicine , concordance , singleton , obstetrics , pregnancy , zygosity , relative risk , fetus , population , gestational age , multiple birth , pediatrics , confidence interval , biology , genetics , environmental health
Objective To determine risk of D own syndrome ( DS ) in multiple relative to singleton pregnancies, and compare prenatal diagnosis rates and pregnancy outcome. Design Population‐based prevalence study based on EUROCAT congenital anomaly registries. Setting Eight European countries. Population 14.8 million births 1990–2009; 2.89% multiple births. Methods DS cases included livebirths, fetal deaths from 20 weeks, and terminations of pregnancy for fetal anomaly ( TOPFA ). Zygosity is inferred from like/unlike sex for birth denominators, and from concordance for DS cases. Main outcome measures Relative risk ( RR ) of DS per fetus/baby from multiple versus singleton pregnancies and per pregnancy in monozygotic/dizygotic versus singleton pregnancies. Proportion of prenatally diagnosed and pregnancy outcome. Statistical analysis Poisson and logistic regression stratified for maternal age, country and time. Results Overall, the adjusted (adj) RR of DS for fetus/babies from multiple versus singleton pregnancies was 0.58 (95% CI 0.53–0.62), similar for all maternal ages except for mothers over 44, for whom it was considerably lower. In 8.7% of twin pairs affected by DS , both co‐twins were diagnosed with the condition. The adj RR of DS for monozygotic versus singleton pregnancies was 0.34 (95% CI 0.25–0.44) and for dizygotic versus singleton pregnancies 1.34 (95% CI 1.23–1.46). DS fetuses from multiple births were less likely to be prenatally diagnosed than singletons (adj OR 0.62 [95% CI 0.50–0.78]) and following diagnosis less likely to be TOPFA (adj OR 0.40 [95% CI 0.27–0.59]). Conclusions The risk of DS per fetus/baby is lower in multiple than singleton pregnancies. These estimates can be used for genetic counselling and prenatal screening.