Prospective risk of stillbirth: monochorionic diamniotic twins vs. dichorionic twins

AIMS: To determine reliably the risk of stillbirth among twin pregnancies. METHODS: A data analysis of 3241 and 6581 women with monochorionic diamniotic (MD) and dichorionic (DD) twins, respectively, who gave birth at ≥22 weeks of gestation. RESULTS: The prospective risk (per 1000 women) of stillbirth, 25.3 and 11.5 at gestational week 22, decreased to <10.0 at gestational weeks 31 and 28 among the MD and DD twins, respectively. After single intrauterine fetal death, the co-twin died in utero or within 7 days of life more frequently among MD twins than among DD twins [42.7% (35/82) vs. 2.6% (2/76); relative risk, 16.2; 95% confidence interval, 4.0-65.1]. CONCLUSION: Women with MD twins were 2.2-fold more likely to experience stillbirth than women with DD twins. The prospective risks of stillbirth were <1.0% for both groups of women at ≥32 weeks of gestation.