Maternal History of Cervical Surgery and Preterm Delivery: A Retrospective Cohort Study.

Introduction: Our aim was to investigate whether cervical conization and/or loop electrosurgical excision procedure (LEEP) increases the risk of preterm delivery. Materials and Methods: We conducted a retrospective cohort study of singleton deliveries at our institution from 2010 to 2015. Women aged 16-49 years were included in our study. Univariate and logistic regression were used for statistical analyses. An interaction test was used to assess whether maternal human papillomavirus (HPV) positivity within the 3 years before delivery (referred to as maternal HPV status in this study) is an effect modifier. Results: Of 3933 women who delivered at our institution, 19.8% (n = 792) delivered prematurely. Of these women, 9.1% (n = 362) had a history of cervical surgery, including cervical conization and/or LEEP. Notably, a history of cervical surgery was not associated with current HPV status based on the most recent Pap smear results (p > 0.05). In univariate analysis, a history of cervical surgery was associated with preterm delivery (odds ratio [OR] = 1.54, 95% confidence interval [CI]: 1.26-1.88). This effect was the same among mothers positive (OR = 1.95, 95% CI: 1.16-3.28) and negative (OR = 1.91, 95% CI: 1.10-3.30) for HPV. Pregnancy-induced hypertension, preterm premature rupture of membranes, bacterial vaginosis infection, HPV infection, placenta previa, placental abruption, ethnicity, maternal body mass index, nulliparity, and smoking or drug use were also associated with preterm delivery (p < 0.05). In multivariable analysis, history of cervical surgery remained associated with preterm delivery (OR = 1.75, 95% CI: 1.31-2.33). There was no interaction (p = 0.91) between maternal HPV status and history of cervical conization or LEEP. Discussion and Conclusions: Maternal history of cervical conization and/or LEEP increases the risk of preterm delivery irrespective of concurrent maternal HPV positivity within the 3 years preceding delivery. Maternal HPV status does not modify the effect of history of cervical conization and/or LEEP on preterm delivery.