Frequency of cerclage in consecutive pregnancies of women with history of preterm birth

BACKGROUND: Serial cervical length screening is performed in women with a history of preterm birth to determine indication for cerclage placement. Our aim is to evaluate the frequency of cerclage placement in consecutive pregnancies with preterm birth history to determine whether performing serial cervical length screening for women with a history of late (34-36 6/7 weeks) spontaneous preterm birth (SPTB) should be reconsidered. METHODS: Retrospective evaluation of cerclage frequency and gestational age of delivery for consecutive singleton births for 69,671 women whose first birth was a SPTB. RESULTS: History of late SPTB was associated with a lower frequency of cerclage than history of early SPTB (0.83% vs 4.88%, OR 0.16, 95% CI 0.14-0.18). Rates of recurrent SPTB were lower for women with history of late SPTB than those with history of early SPTB (13.45%, 3.74% early, 9.71% late vs 20.69%, 9.12% early, 11.57% late). CONCLUSION: Women with a history of late PTB have a lower risk of recurrent PTB than those with a history of early PTB but constitute most of those undergoing serial cervical length screening for potential cerclage placement. Practice guidelines for screening women with a history of late PTB should be re-evaluated.