Pregnancy after Treatment for Cervical Cancer Precursor Lesions in a Retrospective Matched Cohort

OBJECTIVE To determine whether treatments for precancerous cervical lesions were associated with lower pregnancy rates compared to rates in unexposed women and women who had a diagnostic cervical biopsy or colposcopy. DESIGN Matched, retrospective cohort study. SETTING Kaiser Permanente Northwest (KPNW), an integrated healthcare delivery system in Oregon and Washington. PATIENTS Women 14 to 53 years old with KPNW enrollment during the period 1998 through 2009. MAIN OUTCOME MEASURE Pregnancy after exposure or index date. Pregnancy was defined using a validated algorithm and electronic medical records data. RESULTS We observed 570 pregnancies following cervical treatment in 4,137 women, 1,533 pregnancies following a diagnostic procedure in 13,767 women, and 7,436 pregnancies in a frequency-matched sample of 81,435 women unexposed to treatment or diagnostic procedures. After adjusting for age and contraceptive use, we observed a higher rate of pregnancies in the treatment group compared to unexposed women (hazard ratio (HR) = 1.42, 95% confidence interval (CI): 1.30-1.55), but no difference in pregnancy rates between the treatment and diagnostic procedure groups (HR = 1.03, 95% CI: 0.93-1.13). CONCLUSIONS No adverse effects of cervical procedures on subsequent rates of pregnancy were observed in this cohort with up to twelve years of follow-up time.