Perinatologist Corner - C.E.U/C.M.E. Modules
Twins: Antepartum assessment and Intrapartum management
Sponsored by The Indian Health Service Clinical Support Center
7 Twin Pregnancy: Double Trouble?
Step 7. Complications: Fetal complications
In addition to preterm birth, fetal complications include a higher incidence of fetal growth restriction, especially of one twin. (Blickstein) In dichorionic twins this may be because of disadvantageous placentation, with one twin placenta receiving more of the uterine blood flow than the other. In monochorionic twins it may be because of vascular anastomoses with relative hypoperfusion of one twin. In either type of twins it may be because of a fetal anomaly or chromosome problem in one twin. Fetal abnormalities are often discordant in twins, and ultrasonography for fetal anatomy in the early mid-trimester will hopefully detect such problems.
The best way to appreciate fetal growth restriction is by comparing the sonographically estimated fetal weights. A difference of more than 25% in fetal weights is considered to be significantly discordant (larger weight – smaller weight / larger weight). Doppler studies may be indicated (see the Perinatologist Corner module “ Fetal Growth Restriction”). Heightened fetal surveillance with non-stress testing and serial ultrasounds every 3-4 weeks to plot weights will be indicated if the twins are remote from term. Growth restriction with non-reassuring surveillance of one twin may mandate early delivery to prevent stillbirth. (Tan)