Cervical length after multifetal pregnancy reduction in remaining twin gestations

OBJECTIVE: Multifetal pregnancy reduction is associated with an increased r isk of prematurity. Because cervical length correlates with preterm deliver y risk, we sought to determine whether multifetal pregnancy reduction twin gestations are associated with shorter cervical lengths compared with non-m ultifetal pregnancy reduction twins. STUDY DESIGN: We compared an historic cohort of patients who underwent mult ifetal pregnancy reduction to twins (n = 35) to a control group of twin ges tations without multifetal pregnancy reduction (n = 83) from July 1996 to J anuary 2000. Both groups of patients were treated with Identical protocols. Cervical lengths across gestation and pregnancy outcomes were compared. RESULTS: Study and control groups did not differ significantly in mean mate rnal age (37.8 +/- 4.9 years vs 35.5 +/- 6.2 years; P = .06), median parity (0 [range, 0-1] vs 0 [range, 0-2]; P = .56), or mean gestational age at de livery (36.2 +/- 2.6 weeks vs 35.8 +/- 3.8 weeks; P = .50). The proportion delivering before 35 weeks of gestation was not significantly different (14 .3% vs 30.1 % P = .10) nor was delivery before 32 weeks of gestation (8.6% vs 8.4%; P = .98). Cervical length did not differ significantly between the 2 groups. At 14 to 19 weeks the median was 3.9 cm (range, 2.4-6.0 cm) in t he multifetal pregnancy reduction group versus 3.7 cm (range, 3.1-4.7 cm) i n the control subjects (P = .15); at 20 to 25 weeks, the medians were 3.2 c m (range, 2.2-5.4 cm.) and 3.7 cm (range, 1.5-5.7 cm), respectively (P = .4 3); and at 26 to 31 weeks the medians were 3.5 cm (range, 1.2-5.9 cm) versu s 3.8 cm (range, 1.2-5.3 cm), respectively (P = .56). CONCLUSION: Cervical length across gestation in twin pregnancies is not aff ected by multifetal pregnancy reduction, despite the likely inflammatory re sponse expected to accompany this procedure.