First‐trimester growth discordance and adverse pregnancy outcome in dichorionic twins

ABSTRACT Objective To evaluate the association between first‐trimester growth discordance and adverse pregnancy outcome in dichorionic twin pregnancies. METHODS This was a retrospective cohort study of consecutive women with dichorionic twin pregnancies undergoing an ultrasound scan at our institution between 7 and 14 weeks' gestation. Study groups were defined by the presence or absence of ≥ 11% crown–rump length (CRL) discordance. Pregnancies were excluded if one twin was dead on initial ultrasound or if a termination was performed. The primary outcome was loss of one or both fetuses before 20 weeks. Secondary outcomes included fetal anomaly, fetal demise after 20 weeks (stillbirth), small‐for‐gestational‐age (SGA) at birth, admission to the neonatal intensive care unit (NICU) and preterm delivery before 34 weeks. Results Of 805 dichorionic twin pregnancies undergoing first‐trimester ultrasound, 610 met the inclusion criteria. Eighty‐six had ≥ 11% CRL discordance and, of these, nine (10.5%) had a fetal loss at