Eight retrospective studies (n=528) were included.
The initial fixed-effect meta-analysis showed statistically significant heterogeneity. One study was found in a sensitivity analysis to be an outlier, owing to the high infertility rate in medically treated patients. After omission of this study, the meta-analysis was more homogeneous and the fixed-effect meta-analysis was repeated. The relative risk of infertility after IPAA was 3.17 (95% confidence interval, CI: 2.41, 4.18). Using a random-effects model, the relative risk was 2.91 (95% CI: 2.11, 4.02). No evidence of publication bias was found. Further sensitivity analyses only slightly reduced the effect sizes. Using the same studies, a weighted average infertility rate for each treatment group was calculated. Overall infertility was 14.6% after medical management and 48% after IPAA. Patient and procedural risk factors could not be identified.