Multifetal pregnancy is presence of 1 fetus in the uterus.
Multifetal (multiple) pregnancy occurs in up to 1 of 30 deliveries.
Risk factors for multiple pregnancy include
Assisted reproduction (eg, in vitro fertilization)
Prior multifetal pregnancy
Advanced maternal age
West African descent
Complications
Multifetal pregnancy increases the risk of
Neonatal death, largely due to prematurity
The overdistended uterus tends to stimulate preterm labor, causing preterm delivery. Average gestation is
Twins: 35 to 36 weeks
Triplets: 32 weeks
Quadruplets: 30 weeks
Fetal presentation may be abnormal. The uterus may contract after delivery of the first child, shearing away the placenta and increasing risk for the remaining fetuses. Sometimes uterine distention impairs postpartum uterine contraction, leading to atony and maternal hemorrhage.
Some complications develop only in multifetal pregnancies. An example is twin-twin transfusion syndrome (when twins share the same placenta; this syndrome results in vascular communication between the two, which can lead to unequal sharing of blood).
Diagnosis
Prenatal ultrasonography
Multifetal pregnancy is suspected if the uterus is large for dates; it is evident on prenatal ultrasonography.
Treatment
Cesarean delivery when indicated
Cesarean delivery is done when indicated. Cesarean delivery is recommended for twins unless the presenting twin is in vertex presentation. Higher-order multiples are typically delivered by cesarean regardless of presentation.
Key Points
In multifetal pregnancies, the overdistended uterus tends to stimulate preterm labor, resulting in preterm delivery.
Check for other possible complications, such as preeclampsia and gestational diabetes, and prepare for preterm delivery, cesarean delivery, and postpartum hemorrhage.
If the uterus is large for gestational age, do ultrasonography.
For most multifetal pregnancies, deliver by cesarean unless the presenting twin is in vertex presentation.
