Prophylactic Cerclage in the Management of Twin Pregnancies

OBJECTIVE: To determine if prophylactic cerclage improves pregnancy outcomes in women with twin pregnancies without a history of cervical insufficiency. STUDY DESIGN: Women with twin pregnancies who received outpatient preterm labor surveillance services between January 1990 and May 2004 for ≥1 day beginning at < 28.0 weeks' gestation were identified from a database. Patients with previous preterm delivery or a diagnosis of cervical incompetence in a previous or in the index pregnancy were excluded. Twin pregnancies managed with prophylactic cerclage were compared with twin pregnancies in which cerclage was not placed. The primary outcome was incidence of preterm birth prior to 32 weeks. Groups were compared using Fisher exact and Mann-Whitney U test statistics. RESULTS: Overall, 8,218 twin pregnancies met inclusion criteria, of which 146 women (1.8%) received prophylactic cerclage. Patients who received prophylactic cerclage had a significantly higher incidence of preterm birth before 32 weeks and infants with lower mean birth weight and longer nursery stays. No significant difference was seen in mean gestational age at delivery. This study had 80% power to detect a 7% reduction in the primary outcome. CONCLUSION: Prophylactic cerclage was not associated with a lower risk of preterm birth and adverse neonatal outcomes in twin pregnancies without history of cervical insufficiency.