Fetal Surveillance and Timing of Delivery for Multiples.

This chapter describes the current evidence and recommendations for surveillance and delivery timing for multifetal gestations. Ultrasound surveillance should include early determination of chorionicity, anatomic survey for all twins with fetal echocardiography for monochorionic twins, and growth assessment every 4 weeks. Monochorionic twins should also undergo ultrasound surveillance for twin-twin transfusion syndrome every 2 weeks starting at 16 weeks. Weekly testing with nonstress tests or biophysical profiles is recommended at 32 weeks for monochorionic, diamniotic twins, and 34 weeks for dichorionic twins. If this surveillance is reassuring, optimal delivery timing is 36 weeks 0 days to 37 weeks 0 days for monochorionic, diamniotic twins, and 37 week 0 days to 38 weeks 0 days for dichorionic twins.