Prevalence and risk of Down syndrome in monozygotic and dizygotic multiple pregnancies in Europe: implications for prenatal screening.
BJOG
; 121(7): 809-19; discussion 820, 2014 Jun.
Article
in En
| MEDLINE
| ID: mdl-24495335
ABSTRACT
OBJECTIVE:
To determine risk of Down 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 OUTCOMEMEASURES:
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. STATISTICALANALYSIS:
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 adjRR 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 (adjOR 0.62 [95% CI 0.50-0.78]) and following diagnosis less likely to be TOPFA (adjOR 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.Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Pregnancy, Multiple
/
Prenatal Diagnosis
/
Down Syndrome
Type of study:
Diagnostic_studies
/
Etiology_studies
/
Prevalence_studies
/
Risk_factors_studies
/
Screening_studies
Limits:
Adult
/
Female
/
Humans
/
Middle aged
/
Pregnancy
Country/Region as subject:
Europa
Language:
En
Journal:
BJOG
Journal subject:
GINECOLOGIA
/
OBSTETRICIA
Year:
2014
Document type:
Article
Affiliation country: