ABSTRACT
OBJECTIVE: To describe the impact of previous cervical surgery on preterm birth prior to 34 weeks in twins. METHODS: A retrospective review of twin pregnancies delivered between January 1998 and December 2005 at two institutions was performed. Women with a prior cold knife cone (CKC), loop electrosurgical excision procedure (LEEP), or ablative procedure were compared to a control group of women who had not undergone a previous treatment for cervical dysplasia. The primary outcome was delivery before 34 weeks of gestation. RESULTS: A total of 876 women met inclusion criteria. Of these, 110 (12.6%) had previous surgical procedures for cervical dysplasia, including CKC (n = 10), LEEP (n = 36), cryotherapy (n = 59) and CO2 laser treatment (n = 5). Delivery prior to 34 weeks was more common in women with a previous CKC compared to women with no prior treatment (40% versus 11.3%; odds ratio [OR], 3.6; 95% confidence interval [CI], 1.7-8.0). Delivery prior to 34 weeks was not more common in women with a previous LEEP (8.3%; OR, 0.8; 95% CI, 0.3-2.3) or ablative procedure (9.4%; OR, 0.9; 95% CI, 0.4-1.9) in comparison to the untreated group. Adjusting for the potential confounders of age, tobacco use, infertility treatments and previous preterm birth did not change the results. CONCLUSIONS: Previous CKC is associated with delivery prior to 34 weeks while LEEP and ablative procedures are not. CKC should be carefully considered and avoided when possible in reproductive age women.