Clinical outcomes of first trimester discordant twins / 대한산부인과학회지

ABSTRACT

OBJECTIVE: To compare the clinical outcomes of first trimester discordant twins with second or third trimester discordant twins and concordant twins. METHODS: Pregnancy outcomes of twin pregnancies delivered from October 1994 to February 2006 were analyzed retrospectively. Subjects were categorized into following three groups: 1) group 1, first trimester discordant twins defined as intertwin CRL difference > or =5 days at 10-14 weeks of gestation (n=32), 2) group 2, second or third trimester discordant twins defined as intertwin AC difference >20 mm at 20-28 weeks of gestation or intertwin fetal weight difference >25% beyond 29 weeks of gestation (n=42), 3) group 3, concordant twins with no discordancy throughout the whole gestation (n=723). Perinatal complications analyzed for were congenital anomaly, fetal growth restriction (FGR), fetal death in utero (FDIU). RESULTS: The three groups were similar with respect to maternal characteristics and chorionicity. Overall, the group 2 had higher perinatal complications compared to the group 3. Congenital anomaly was more common in the group 1 than the group 2 (21.9% vs. 11.9%, p<0.001). However, FGR rate was higher in the group 2 than the group 1 (32.3% vs. 71.8%, p<0.01). Congenital anomaly, FGR and FDIU were more common in the group 1 compared to the group 3 (21.9% vs. 3.5%, p<0.001, 32.3% vs. 9.1%, p<0.01, 6.3% vs. 1.0%, p<0.05, respectively). CONCLUSIONS: First trimester discordant twins have an increased risk of congenital anomaly, FGR and FDIU, and therefore, they should be regarded as a high-risk pregnancy likewise second or third trimester discordant twins.