Impact of Pregnancy on Hidradenitis Suppurativa Disease Course: A Systematic Review and Meta-Analysis

Background: Hormones are thought to play a role in hidradenitis suppurativa (HS). However, data on the HS disease course during pregnancy and the postpartum period has not been well established. The objective of this study is to analyze the available literature to determine HS disease activity during pregnancy and the postpartum period. Methods: The PubMed and Embase databases were systematically searched for relevant articles from database inception until November 22, 2020. The inclusion criteria were a study population with the diagnosis of HS and discussion of pregnancy impact on the HS disease course or postpartum flare. Study characteristics, patient demographics, HS severity, and HS disease course during pregnancy and the postpartum period were extracted by 2 independent reviewers. The quality of included studies was assessed using the Newcastle-Ottawa Scale for observational studies. Heterogeneity was assessed using Cochran's Q statistic and I-2 index. The random-effects meta-analytical model was used. The primary study outcome was the pooled odds ratio of improvement or of worsening of HS disease activity during pregnancy. Results: The systematic search identified 8 studies for analysis. There was a total of 672 cases for which data on the patient-reported HS disease course during pregnancy were available, and 164 cases for which data on patient-reported postpartum flare were available. In the meta-analyses, the rate of HS disease improvement was 24% (95% CI 0.13-0.40) and the rate of HS disease worsening was 20% (95% CI 0.11-0.34). Sixty percent (99/164) of patients experienced a postpartum flare. Conclusion: While about a quarter of women will experience an improvement in HS during pregnancy, the majority will have a stable or worsened disease course, and over half of patients will experience a postpartum flare. Close monitoring of HS patients is needed during pregnancy and postpartum periods, as patients may need continued, or even escalated, disease management.