Ultrasound examination in twin pregnancies

Twins are at higher risk of complications in pregnancy than singletons, especially when they are monochorionic. Complications to be aware of are twin-to-twin transfusion syndrome, intrauterine growth restriction and structural abnormalities. Determining chorionicity in the first trimester is relevant in every twin pregnancy. Ultrasound examination can be used to optimize prenatal care and should therefore be performed every 2 weeks.