Prospective risk of fetal death in uncomplicated monochorionic twins


Dr Nadine Farah, Consultant Obstetrician and Gynaecologist, Coombe Women and Infants University Hospital, Cork Street, Dublin 8. E-mail:

Conflict of Interest
The authors have stated explicitly that there are no conflicts of interest in connection with this article.The authors alone are responsible for the content and writing of the paper.


A retrospective cohort study was carried out in a university teaching hospital to determine the prospective risk of unexpected fetal death in uncomplicated monochorionic diamniotic (MCDA) twin pregnancies after viability. All MCDA twins delivered at or after 24 weeks’ gestation from July 1999 to July 2007 were included. Pregnancies with twin–twin transfusion syndrome, growth restriction, structural abnormalities, or twin reversed arterial perfusion sequence were excluded. Of the 144 MCDA twin pregnancies included in our analysis, the risk of intrauterine death was 4.9%. The prospective risk of unexpected intrauterine death was 1 in 43 after 32 weeks’ gestation and 1 in 37 after 34 weeks’ gestation. Our results demonstrate that despite close surveillance, the unexpected intrauterine death rate in uncomplicated MCDA twin pregnancies is high. This rate seems to increase after 34 weeks’ gestation, suggesting that a policy of elective preterm delivery warrants evaluation.