Twin pregnancies are considered to be high-risk, with a thirteenfold higher rate of stillbirth and a fivefold higher rate of dichorionic twins, when compared with singleton pregnancies. This study aims to evaluate the risks of stillbirth and neonatal complications by gestational age in uncomplicated monochorionic and dichorionic twin pregnancies.

This was a systematic review and meta-analysis of 32 studies of women with uncomplicated twin pregnancies with stillbirth and neonatal outcomes at different gestational ages. The primary outcomes of the study were prospective risk of stillbirth and a gestational age-specific difference in risk.

A delay in delivery by a week was associated with an additional 8.8 perinatal deaths per 1,000 pregnancies. In monochorionic pregnancies beyond 34 weeks (balanced at 37 weeks’ gestation), a positive association towards an increase in stillbirths vs. neonatal deaths after 36 weeks was observed. However, the increase in stillbirths was 2.5 per 1,000 perinatal deaths, which was not statistically significant. The findings further suggested that the rates of neonatal morbidity were inversely associated with increasing gestational age in monochorionic and dichorionic pregnancies.

The research concluded that uncomplicated dichorionic twin pregnancies delivery should be considered at 37 weeks’ gestation and monochorionic pregnancies at 36 weeks’ gestation for reducing the risk of perinatal deaths.

Ref: https://www.bmj.com/content/354/bmj.i4353