Second‐trimester discordance and adverse perinatal outcome in twins: the STORK multiple pregnancy cohort

Objective The aim of this study was to determine the association between biometry discordance at the time of the anomaly scan and adverse perinatal outcomes in twin pregnancies. Design Retrospective cohort study. Setting Nine hospitals in the Southwest Thames Region of London Obstetric Research Collaborative (STORK). Population or sample Population multicentre retrospective study of all twin pregnancies booked for antenatal care in nine hospitals over a period of 10 years. Methods Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to evaluate the association between abdominal circumference (AC) and estimated fetal weight (EFW) discordance, recorded between 20 and 22 weeks of gestation, and adverse pregnancy outcomes. Main outcome measures Stillbirth, neonatal mortality, preterm birth (PTB) at