Characterizing perinatal treatment patterns and outcomes in rheumatologic disease: A retrospective cohort study in a US health insurance claims database

Background: Pregnancy among those with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), and Sjögren’s disease (SjD) has been associated with maternal and fetal complications, thus presenting challenges for clinical management and therapeutic decision-making. However, studies are often limited by small sample size or focus on a limited number of perinatal outcomes.

Objectives: To characterize treatment patterns in pregnancy and estimate the prevalence of adverse perinatal outcomes among individuals with RA, SLE, and SjD.

Methods: We conducted a retrospective cohort study in the United States (US) Marketscan Commercial Claims and Encounters database between 2000-2022. Pregnancies in females aged 18-49 were identified and among live births, maternal and infant records were linked. RA, SLE, and SjD were defined by ≥2 diagnoses within a 365-day period and ≥1 diagnosis before the end of pregnancy. The prevalence of six perinatal outcomes was calculated in the RA, SLE, SjD and total populations: spontaneous abortion, stillbirth, Cesarean section, preeclampsia, preterm birth, and small for gestational age (SGA). Outcome prevalence in the total population was standardized to the RA, SLE, and SjD population age distributions. Condition-specific treatments were summarized at the class level and included corticosteroids, non-steroidal anti-inflammatory drugs, non-biologic disease modifying anti-rheumatic drugs (dMARDs), biologic dMARDs, as well as known teratogens.

Results: Among those with RA (n=7,029), SLE (n=6,996), and SjD (n=2,259), the proportions of patients receiving no treatment increased from preconception to pregnancy: 29.4% to 42.2%, 36.0% to 42.7%, and 43.1% to 51.0%, respectively. Among the 33.6%, 29.8%, and 22.5% on corticosteroids in pregnancy, 35.3%, 38.7% and 50.0% had not taken them in preconception across RA, SLE, and SjD, respectively. The prevalence of spontaneous abortion and stillbirth was greater in RA (23.5% vs. 22.4%, p=0.01 and 0.6% vs. 0.4%, p=0.03, respectively) and SLE (24.0% vs. 21.7%, p<0.01 and 0.7% vs. 0.4%, p<0.01, respectively), though not in SjD (22.4% vs. 22.7%, p=0.70 and 0.5% vs. 0.4%, p=0.37, respectively) pregnancies than the age-adjusted total populations. Across all conditions, the risks of preterm birth, SGA, Cesarean section, and preeclampsia were greater than among the age-adjusted total populations. The largest relative differences were observed for preterm birth and SGA, and across conditions, the largest differences were in SLE.

Conclusions: RA, SLE, and SjD were associated with a greater burden of several perinatal outcomes, suggesting an unmet need for this population. In parallel, treatment patterns were dynamic in the perinatal period, suggesting a need for safe treatments in pregnancy.