Contemporary management of monochorionic diamniotic twins: outcomes and delivery recommendations revisited

OBJECTIVE: We sought to investigate outcomes of contemporaneously managed monochorionic diamniotic (MCDA) twins, stratified by pregnancy complication. STUDY DESIGN: Four hundred eighteen MCDA pregnancies from 2001 through 2008 were retrospectively reviewed. RESULTS: There were 236 ongoing pregnancies at 24 weeks' gestation. The likelihood of progressing from 24 weeks to 2 live births was 98.7% in uncomplicated pregnancies, 89.7% with twin-twin transfusion syndrome, and 100% with growth discordance, increasing at 32 weeks to 99.5%, 93.8%, and 100%, respectively. The relative risk (RR) of birth <32 weeks was significantly greater in twin-twin transfusion syndrome (RR, 4.1; 95% confidence interval, 2.7-6.1) and growth discordant (RR, 2.1; 95% confidence interval, 1.8-3.8) pregnancies than in uncomplicated pregnancies (P<.0001). CONCLUSION: This represents one of the largest cohorts of MCDA twins. The risk of third-trimester fetal loss was low. The likelihood of both intrauterine fetal demise and preterm birth were greater in complicated pregnancies. In the absence of a clinical indication for delivery, these data do not support elective preterm delivery for prevention of intrauterine fetal demise in uncomplicated MCDA twins.