The Effect of Loop Electrosurgical Excision Procedure on Future Pregnancy Outcome

OBJECTIVE: To estimate whether the loop electrosurgical excision procedure (LEEP) is associated with an adverse effect on the outcome of subsequent pregnancies. METHODS: A retrospective cohort study was performed. The study group comprised women who had a LEEP in Halifax County between 1992 and 1999 and then had a subsequent singleton pregnancy of greater than 20 weeks of gestation with delivery at the IWK Health Centre in Halifax, Nova Scotia. The comparison group comprised women with no history of cervical surgery who were matched for age, parity, smoking status, and year of delivery. There were 571 women in each group. The primary outcome was rate of preterm delivery at less than 37 weeks of gestation. Secondary outcomes included delivery at less than 34 weeks and various neonatal and maternal outcomes. The effect of specific LEEP characteristics was analyzed separately. RESULTS: Women who had a LEEP were more likely to deliver preterm overall (7.9% versus 2.5%; odds ratio OR 3.50, 95% confidence interval CI 1.90-6.95; P < .001) and to deliver preterm after premature rupture of membranes (PROM) (3.5% versus 0.9%; OR 4.10, 95% CI 1.48-14.09). The increase in delivery at less than 34 weeks was not statistically significant (1.25% versus 0.36%; OR 3.50, 95% CI 0.85-23.49; P = .12). Women with LEEP also delivered more low birth weight (LBW) infants (5.4% versus 1.9%; OR 3.00, 95% CI 1.52-6.46; P = .003). There were no differences in other neonatal or maternal outcomes. No association was found between the characteristics of the LEEP, including depth, and the rate of preterm delivery. CONCLUSION: Loop electrosurgical excision procedure is associated with an increased risk of overall preterm delivery, preterm delivery after PROM, and LBW infants in subsequent pregnancies at greater than 20 weeks of gestation. Women who are considering future pregnancies should be counseled about these risks during informed consent for LEEP. LEVEL OF EVIDENCE: II-2.