Comorbidities and Disease Type Weigh Heavily in Pregnancy Outcomes of Immune-Mediated Inflammatory Diseases

A Large Study, But How Representative Is It?

Asked to comment on the study, Catherine Sims, MD, a rheumatologist at Duke University Medical Center in Durham, North Carolina, noted that the analysis was much larger than many reproductive rheumatology studies, and “their statistics were phenomenal.”

She agreed that “not all autoimmune diseases are created equal when it comes to pregnancy-associated risks.” However, she added that this study’s patient population may not be totally representative of pregnant people with IMIDs or autoimmune diseases.

“We’re making generalizations about autoimmune diseases based on this demographic of White women who are not taking immunosuppression,” she said.

“We know that race and ethnicity play a huge role in pregnancy outcomes, and Black women have higher maternal and fetal morbidity and mortality, which is likely related to systemic racism and biases in the medical system,” she added. “While the study did control for sociodemographic factors, the population studied is not diverse.”

Only 17% of people with IMID in the cohort were on immunosuppressive medication, which could suggest low disease activity in the study population, Dr. Sims said. If the population generally had well-controlled disease, that could have positioned them for better pregnancy outcomes.

The authors noted that their analysis did not have information on IMID disease activity or severity — one of the limitations of the study.

However, the authors argued that the observed low prescription rate during the study may have increased poor pregnancy outcomes.

“Although this reflects real-world care in the population studied, results from this study may show higher risk than might be achieved with recommended care guidelines,” they wrote.

Ultimately, the authors argued that these findings show how co-occurring health conditions can affect pregnancy outcomes in autoimmune diseases, particularly for RA and IBD.

“There is a need to take comorbidities into consideration for guidelines for patients with inflammatory bowel disease and rheumatoid arthritis and when designing future research to investigate maternal health in patients with IMIDs,” they wrote.

The study was funded by the National Institutes of Health. Dr. Sims declared no relevant financial relationships. Dr. Hadlock has received research funding (paid to the institute) from Pfizer, Novartis, Janssen, Bristol-Myers Squibb, and Gilead.

A version of this article first appeared on Medscape.com.