Cheong-See and colleagues conducted a comprehensive review and analysis of 32 studies of uncomplicated dichorionic and monochorionic twin pregnancies to determine the risks of stillbirth and neonatal complications by gestational age.
Details of the study
The authors searched major databases for studies on twin pregnancies that reported rates of stillbirth as well as neonatal outcomes (neonatal mortality was defined as death up to 28 days after delivery). A total of 32 studies were included in the analysis, with 29,685 dichorionic and 5,486 monochorionic pregnancies in 35,171 women. The authors estimated the gestational-age specific differences in risk for stillbirths and neonatal deaths after 34 weeks’ gestation.
In dichorionic pregnancies, the prospective weekly pooled risk of stillbirths from expectant management and the risk of neonatal mortality from delivery were balanced at 37 weeks of gestation (risk difference, 1.2/1,000, 95% CI, −1.3 to 3.6; I2 = 0%). In monochorionic pregnancies, after 36 weeks there was a trend toward an increase in stillbirths compared with neonatal deaths, with a pooled risk difference of 2.5/1,000 (95% CI, −12.4 to 17.4; I2 = 0%). Neonatal morbidity rates were consistently reduced with increasing gestational age in both monochorionic and dichorionic pregnancies.