“Hidradenitis suppurativa (HS) disproportionately affects women aged 18-39, during childbearing years,” explains Jennifer Hsiao, MD. “Data also suggest a possible increased risk of adverse pregnancy and maternal outcomes in patients with psoriasis, another inflammatory skin disease. In addition, women with systemic inflammatory diseases like systemic lupus erythematosus, rheumatoid arthritis, and inflammatory bowel disease have been found to have adverse pregnancy outcomes. Since HS is a disease with a systemic inflammatory burden, it is important to study whether HS also imparts increased risk for adverse pregnancy and maternal outcomes.”

 For a paper published in the Journal of the American Academy of Dermatology, Dr. Hsiao and colleagues compared the risk for adverse pregnancy and maternal outcomes among women with and without HS and evaluated the influence of comorbid conditions. Their retrospective cohort study used a multi-health system data analytics platform with a database that included 26 participating United States healthcare organizations and data from more than 64 million people across all census regions and insurance types. The study population included women aged 12-55, with or without HS and at least one ICD-9 code for pregnancy. Primary outcomes included spontaneous abortion, stillbirth, preterm birth, gestational diabetes, gestational hypertension, preeclampsia, and cesarean section. The frequency of each of these outcomes was calculated and compared between patients with and without HS.

Comorbidities Linked With Adverse Pregnancy Outcomes

“Patients with HS have several comorbidities that are associated with adverse pregnancy outcomes, including smoking, diabetes, and hypertension,” Dr. Hsiao notes. “For each adverse outcome, a unique and relevant set of covariates were adjusted for in the regression models (ie, in gestational hypertension, the regression model adjusted for age, race, obesity, pre-existing diabetes, renal disease, and tobacco smoking).

Dr. Hsiao and colleagues found that pregnant women with HS were at increased risk for adverse pregnancy and maternal outcomes. “Early management of modifiable HS comorbidities, such as pre-existing hypertension and smoking, may mitigate some of these adverse outcomes,” Dr. Hsiao adds. “However, even after controlling for comorbidities, HS was still an independent risk factor for increased adverse outcomes for pregnant women.”

There were 1,862 pregnancies among 1,600 women with HS and 64,218 pregnancies among 53,278 women without HS (the control population). After adjusting for age and race, the study team found that—when compared with pregnant women without HS—pregnant HS women had a significantly increased risk for several adverse pregnancy and maternal outcomes. These included spontaneous abortion (OR, 1.37; 95% CI, 1.20-1.57), preterm birth (OR, 1.25; 95% CI, 1.04-1.50), gestational diabetes (OR, 1.59; 95% CI, 1.36-1.86), gestational hypertension (OR, 1.38; 95% CI, 1.11-1.72), pre-eclampsia (OR, 1.57; 95% CI, 1.29-1.90), and cesarean section (OR, 1.19; 95% CI, 1.10-1.29). After controlling for comorbidities, pregnant women with HS still had an increased risk of spontaneous abortion (OR, 1.20; 95% CI, 1.04-1.38), gestational diabetes (OR, 1.26; 95% CI, 1.07-1.48), and cesarean section (risk ratio, 1.09; 95% CI, 1.004-1.17; Table).

Strong Clinical Collaboration Needed

“Our study findings may help dermatologists and obstetricians better counsel women with HS who are planning for pregnancy and better manage and monitor these patients,” Dr. Hsiao says. “Women with HS who are pregnant need to be followed closely, and their associated comorbidities managed early, given their increased risk for adverse pregnancy and maternal outcomes. Strong collaboration is needed between dermatologists and obstetricians to optimize care for these patients and balance the potential risk of utilizing HS medications during pregnancy against the risk of uncontrolled HS disease and inflammation during pregnancy.”

Dr. Hsiao and colleagues say future research should examine whether increased HS severity correlates with increased risk of adverse pregnancy and maternal outcomes. “Along those lines, studies are also needed to investigate whether treatment of HS during pregnancy may attenuate this risk,” she says.