Perinatal outcome of twin pregnancies in women of advanced age

BACKGROUND: The aim of this study was to assess the outcome of twin pregnancies in women of advanced age (≥35 years) compared with women aged 25-29 years old. METHODS: This population-based retrospective study compared perinatal outcome of twin pregnancies in primiparae aged 35 or older (N = 240) to that of twin pregnancies in primiparae aged 25-29 years (N = 940). Observed outcomes are adjusted for intermediate (mode of conception and hypertension during pregnancy) and confounding variables (level of education). The possible effect of zygosity and chorionicity was tested in a subset of this database, recorded in the East Flanders Prospective Twin Survey (EFPTS). RESULTS: In twin pregnancies, maternal age of 35 or over is associated with a lower incidence of preterm birth [adjusted odds ratio (AOR) 0.59, 95% confidence interval (CI) 0.44-0.79] and low birthweight (AOR 0.75, 95% CI 0.58-0.98) compared with younger women. Differences in zygosity and chorionicity between both cohorts do not seem to affect the result. CONCLUSIONS: In comparison with primiparae aged 25-29 years, perinatal outcome of twin pregnancies is more favourable in primiparae aged 35 or over.