The impact of advanced maternal age (> or = 40 years) on birth outcomes among triplets: a population study.

Abstract

The objective was to determine the impact of advanced maternal age on the birth outcomes of triplet gestations. A retrospective cohort study on 15,795 triplets born in the United States from 1995 to 1997. The generalized estimating equations framework was used to generate relative risks after capturing the effect of sibling correlations within triplet clusters. There was a 40% higher likelihood for stillbirths among older gravidas (> or = 40 years) as compared to younger mothers (20-29 years) although this was statistically non-significant. By contrast, we noted a significantly lower level of neonatal mortality (OR=0.36, 95% CI=0.19-0.67), perinatal mortality (OR=0.53; 95% CI=0.32-0.89) and infant mortality (OR=0.37; 95% CI=0.20-0.67) among older mothers. Our findings demonstrate a "shifting phenomenon" whereby a higher level of intra-uterine demise was compensated by a higher rate of extra-uterine survival among triplets born to older mothers.