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.