A systematic approach to first-trimester ultrasound assessment of twins.

The incidence of twin pregnancies has increased for the last 20 years mainly as a result of assisted reproduction technologies and pregnancies occurring in older women. Both maternal and perinatal mortality and morbidity are increased in twin pregnancies when compared with singletons. A systematic and detailed first-trimester ultrasound can be a useful tool for detecting chorionicity, growth discordance, and congenital malformations. Prediction of complications at an early stage can help with directing future management and counseling of patients. Copyright Thieme Medical Publishers.