Perinatal outcome after fetal reduction from twin to singleton: to reduce or not to reduce?

Objective: To determine whether reduction of twin gestation to singleton pregnancy is associated with improved perinatal outcome.

Design: A retrospective cohort study.

Setting: Single tertiary care medical center.

Patient(s): A cohort of 63 singleton pregnancies after reduction from dichorionic-diamniotic twins gestation and 62 dichorionic-diamniotic nonreduced twins.

Intervention(s): Fetal reduction between 11 and 14 weeks of gestation.

Main outcome measure(s): Obstetric outcome.

Result(s): The rates of preterm delivery at <34 weeks (1.6% in pregnancies after reduction vs. 11.7% in nonreduced twins) and at <37 weeks of gestation (9.5% vs. 56.7%) were significantly lower in patients whose pregnancies were reduced to singletons. The rates of miscarriage of one twin (0% vs. 4.8%) and early pregnancy loss before 24 weeks of gestation as well as the rates of gestational diabetes (11.1% vs. 10%), hypertensive diseases of pregnancy (6.3% vs. 15%), and intrauterine growth restriction (0% vs. 3.3%) were similar in both groups.

Conclusion(s): Fetal reduction of twins to singleton is associated with a lower risk of prematurity and superior perinatal outcome compared with nonreduced twins. Therefore, the option of fetal reduction should be considered in certain cases of twin pregnancies, where the risk for adverse outcome seems exceptionally high.