Perinatal complications of monochorionic diamniotic twin gestations with discordant crown-rump length determined at mid-first trimester

The aim of this study was to investigate the value of discordance of crown-rump length (DCRL) at mid-first trimester to predict adverse outcomes in monochorionic diamniotic twin gestations (MD).

This was a retrospective cohort study of the perinatal outcome in MD pregnancies managed from the first trimester onward. DCRL was evaluated between 8 and 10 weeks of gestation. The association between DCRL and perinatal complications, including fetal death, twin-twin transfusion syndrome, severe discordant birthweight (DB), and twin anemia-polycythemia sequence, was assessed.

Among 126 cases, a single fetal demise occurred in two (2%) and demise of both fetuses occurred in eight (6%). Five pregnancies (4%) were complicated with twin-twin transfusion syndrome; one case (1%) was twin anemia-polycythemia sequence and 13 (10%) were DB. Neonatal death occurred in one pair. At 28 days of age, in 115 cases (91%) both twins were alive. In 117 cases (93%), at least one twin survived until 28 days of age. DCRL >12.0% was not related to any perinatal complications but DB (P < 0.01; relative risk: 1.40; 95% confidence interval: 1.06-1.84).

DCRL in MD during the mid-first trimester might be useful for predicting DB.