The outcome measures, which were stratified by chorionicity, were: first, death of both fetuses at presentation or death of one fetus followed by delivery of a live or dead co-twin within the subsequent 3 days at <34 weeks' gestation second, in pregnancies with single fetal death at <34 weeks' gestation and the co-twin being alive for ≥3 days, subsequent risk of fetal death and gestational age distribution at birth of the co-twin and third, gestational age distribution at birth of pregnancies with two live fetuses. This was a retrospective analysis of prospectively collected data on twin pregnancies undergoing routine ultrasound examination at 11-13 weeks' gestation between 20.

First, to compare the incidence of single and double fetal death in monochorionic (MC) and dichorionic (DC) twin pregnancies with two live fetuses at 11-13 weeks' gestation and no major abnormalities, second, to investigate the relationship between the gestational age at single fetal death and interval to delivery of the co-twin, and third, to determine the rate of early preterm birth in DC and MC twin pregnancies with two live fetuses and those with single fetal death.

Lost twins at 13 weeks