Only once chorionicity is correctly assigned can appropriate follow up be planned for a twin pregnancy. Dichorionic twins, considered the ësafestí type of twin pregnancy, remain at increased risk of preterm birth, structural abnormalities, and intra-uterine fetal death. Second trimester ultrasound can screen for these complications, enabling best practice management. But should we always screen, just because we can? The pros and cons of cervical length screening in asymptomatic twin pregnancies will be discussed.
Third trimester ultrasound follow-up is centered around the detection of fetal growth restriction, which has additional challenges in twin pregnancies compared to singletons. Which measurements give the most accurate estimated fetal weights? Should specific twin growth charts be used? Do the changes in Doppler studies mirror those of singleton pregnancies? Understanding the answers to these questions will guide the most appropriate third trimester follow-up of dichorionic twin pregnancies.