Effect of oral contraceptive use on reoperation following surgery for Crohn's disease

Abstract

The influence of oral contraceptive (OCP) use as a risk factor for the development of Crohn's disease is disputed. We wished to determine if OCP use affected the risk of recurrence (defined as need for a second surgery) in women who had already undergone a resection for Crohn's disease. We hypothesized that if contraceptive use was a risk factor for disease development, it could influence recurrence. Using a mail questionnaire, we surveyed 138 women regarding their OCP use following surgery for Crohn's disease. All participants were between ages 16 and 35 at the time of their initial surgery which occurred between 1966 and 1984. Ninety-seven women (70%) responded. Mean follow-up was 9.9 years (range 4–27). Forty-six women required a second surgery. The recurrence rate as determined by actuarial analysis, was 27.2% (95% confidence intervals (CI₉₅ 16.5–38.1) and 58.0% (CI₉₅ 37.8–78.2) at 5 and 10 years, respectively. Thirty-two women took OCP in the first year following surgery. Eleven OCP users (34.4%) required additional surgery compared to 34 (53.1%) of nonusers. Using life table analysis, the percentage requiring a second surgery was 25.0% (CI₉₅ 6.9–43.1) and 40.7% (CI₉₅ 1.5–80%) at 5 and 10 years, respectively, for users compared to 28.4% (CI₉₅ 6.9–43.1) and 64.0% (CI₉₅ 40.5–87.5) for nonusers (Lee Desu, P>0.05). When surveyed about their reasons for using OCP, most women stated that their disease did not affect their decision to use contraceptives. There were no significant differences in terms of reasons for using OCP between those who required surgery and those who did not. In conclusion, there was little evidence to support the hypothesis that OCP use increased the risk of requiring a second operation in women who had undergone surgery for Crohn's Disease. The small sample size may have prevented detection of a modest effect.