Cervical surgery for cervical intraepithelial neoplasia and prolonged time to conception of a live birth: a case-control study

Objective To determine whether women with a history of surgery for cervical intraepithelial neoplasia (CIN) are at an increased risk of subfertility, measured as a time to pregnancy of more than 12months. Design Case-control study. Setting Iowa Health in Pregnancy Study (IHIPS), a population-based case-control study of preterm and small-for-gestational-age (SGA) live birth outcomes (from May 2002 through June 2005) in the USA. Sample Women with an intended pregnancy and a history of either one prior cervical surgery (n=152), colposcopy only (n=151), or no prior cervical surgery or colposcopy (n=1021). Methods Cervical treatment history, pregnancy intention, time to pregnancy, and other variables were self-reported by computer-assisted telephone interviews. Odds ratios were calculated using logistic regression to estimate the risk of prolonged time to pregnancy among women with a history of cervical surgery or colposcopy alone, compared with untreated women (control group). Main outcome measure Prolonged time to pregnancy (i.e. >1year). Results Prolonged time to pregnancy was most prevalent among treated women (16.4%), compared with untreated women (8.4%) and women with colposcopy only (8.6%) (P=0.039). After adjusting for covariates, women with prior cervical surgery had a more than two-fold higher risk of prolonged time to pregnancy compared with untreated women (aOR2.09, 95%CI 1.26-3.46). In contrast, women with a history of colposcopy only had a risk equivalent to that found among untreated women (aOR1.02, 95%CI 0.56-1.89). Conclusions Women with a history of cervical treatment for CIN are at increased risk of subfertility, measured as a time to pregnancy of more than 12months.