SAN DIEGO — , results from a large case-control study suggest.
Patients with systemic autoimmune conditions are known to have an increased risk for adverse pregnancy outcomes, “but we weren’t sure if that was the case for patients with autoimmune skin conditions,” presenting study author Heejo Keum, a fourth-year medical student at the University of Texas Southwestern Medical Center, Dallas, said in an interview during a poster session at the American College of Rheumatology (ACR) 2023 annual meeting. “There are case reports or nationwide population-based studies on patients with alopecia areata and vitiligo, but those were outside of the US, so we wanted to see if these outcomes could be studied in a larger population-based study in the US.”
Doug Brunk/MDedge News
Heejo Keum
Drawing from the TriNetX US Collaborative Network, a database of electronic medical records of 94 million patients in the United States, the researchers identified pregnant patients aged 15-44 years between January 1, 2016, and December 31, 2021. Cases were defined as patients diagnosed with at least one autoimmune skin disease (ASD) prior to the end of pregnancy, including alopecia areata, bullous pemphigoid, cicatricial pemphigoid, dermatitis herpetiformis, cutaneous lupus erythematosus, epidermolysis bullosa acquisita, morphea, pemphigus foliaceus, pemphigus vulgaris, vitiligo, and amyopathic DM. There were two control groups: healthy controls (those without ASDs, systemic lupus erythematosus or rheumatoid arthritis) and disease controls (those with SLE or RA). The researchers used ICD-10 codes to identify pregnancy endpoints, including live births, spontaneous abortion, and stillbirth. Patients with a history of hidradenitis suppurative were excluded from the analysis, as were those with common autoimmune disease such as Hashimoto’s thyroiditis, Grave’s disease, and type 1 diabetes.
The primary outcomes were adverse pregnancy outcomes defined as spontaneous abortion, gestational hypertension, preeclampsia/eclampsia, gestational diabetes, intrauterine growth restriction (IUGR), preterm premature rupture of membranes (PPROM), and preterm birth. The researchers used 1:1 propensity scoring to match patients with ASDs to controls by age, race, ethnicity, comorbidities, obesity, and substance use, and used odds ratio (OR) analysis with a 95% confidence interval (CI) to calculate each outcome.
Ms. Keum reported results from 3,654 women with ASDs, 3,654 healthy controls, 2,147 women with SLE, and 889 women with RA.
The three most common ASDs were vitiligo (30%), alopecia areata (30%), and cutaneous lupus erythematosus (27%). Compared with healthy controls, patients with ASDs were more likely to have spontaneous abortions (OR=1.5 [1.4-1.7], P<.001), and preeclampsia/eclampsia (OR=1.2 [1.0-1.3], P=.04). Compared with women with SLE, women with ASDs were less likely to have preeclampsia/eclampsia (OR=0.7 [0.6-0.9, P=.001); preterm birth (OR= 0.5 [0.4-0.7], P<.001); PPROM (OR=0.6 [0.4-0.9], P=.004), or an infant with IUGR (OR=0.6 [0.5-0.8], P<.001), but they were more likely to have a spontaneous abortion (OR=1.2 [1.1-1.3], P=.003). Overall, patients with ASDs had similar risks for adverse pregnancy outcomes as patients with RA.
“We found that patients with cutaneous lupus and vitiligo had higher rates of spontaneous abortion, which is interesting because we didn’t expect that,” Ms. Keum told this news organization. “Studies have shown that vitiligo patients might have an increased risk of pregnancy loss, so I think it’s important to have that discussion with those patients. It might benefit them to talk to a maternal-fetal medicine specialist. As for next steps, we want to look at how medication use and disease flare or disease severity play a role in APOs.”
In their poster, the researchers acknowledged limitations of the study, including the inability to verify diagnoses or assess disease severity. Also, while medication use and concomitant antiphospholipid syndrome were evaluated as risk factors for advanced pregnancy outcomes, the number of patients per group was too small for analysis.
Karl Saardi, MD, director of the inpatient dermatology service at George Washington University Hospital, Washington, who was asked to comment on the study, said that in his view, the choice of disease states included in the analysis “is a bit arbitrary.” He added that “it would have been more helpful to compare controls versus discoid lupus versus systemic lupus or controls versus amyopathic dermatomyositis versus dermatomyositis with myopathy.”
The study received funding support from the Rheumatology Research Foundation and the UT Southwestern Dean’s Research Scholar program. Neither Ms. Keum nor Dr. Saardi reported having relevant disclosures.