Background Women with systemic lupus erythematosus (SLE) historically have worse pregnancy outcomes as compared to their healthy age-matched counterparts. Auto-antibodies associated with conditions such as SLE are detected in the serum of patients several years prior to their diagnosis and are more prevalent among those with a family history of SLE. Prior studies show that adverse pregnancy outcomes occurred at a rate higher than controls even before diagnosis of SLE, suggesting a pre-disease state. We hypothesize there is a pre-disease state impacting pregnancy outcomes among women with circulating SLE-associated autoantibodies noted prior to a diagnosis of SLE. To address this hypothesis, we evaluate the differences in outcomes between patients with SLE and two groups of controls.

Methods Data on women with at least one prior recorded pregnancy was obtained from an ongoing longitudinal registry at a single center. Information on demographics, pregnancy history, social, family, and medical histories was obtained through in person interviews and chart review. All SLE patients included met ACR classification criteria for the disease. Auto-antibody positive was defined as ANA (≥1:80) and/or lupus antibody positive (including anti-Smith, double-stranded DNA, and/or antiphospholipid antibody positive). Infertility is defined as attempting to conceive for >1 year without conception. Pearson’s chi-squared testing was performed for categorical measures and two-sample t-tests for continuous measures.

Results Patients and controls were predominantly Black and had a mean of 1.85 live births per individual. Women with SLE had a total of 828 live births with 710 live births in the control group (434 from related controls). Preeclampsia was seen in 74 women with SLE and 21 controls (11 related controls), table 1. Low birth weight was seen in 101 women with SLE and 28 controls (17 related controls). Premature gonadal failure was seen in 1.8% of patients with SLE. Infertility was not significantly different between SLE and all controls. A higher proportion of related controls were ANA positive (47.7%) as compared to unrelated controls (30.5%).

Comparing ANA positive to ANA negative controls, there was not a significant difference between proportion of women having a live birth (95.8% vs 97.9%), low birth weight (12.6% vs 11.5%), prematurity (9.2% vs 12.3%), preeclampsia (9.2% vs 8.5%), or infertility 3.3% vs 2.1%).

Conclusion In a large cohort of predominantly Black women, we note differences in pregnancy outcomes among women with SLE compared to related and unrelated controls. A high rate of ANA positivity was noted in the control groups, increased further in related controls, which is above previously reported general population estimates. Adverse pregnancy outcomes (such as preeclampsia and low birth weight) were seen in those with SLE at a higher rate than controls. In ANA positive controls, there was a trend towards increased rates of adverse outcomes.

Future analysis will evaluate the timing of SLE pregnancy outcomes prior to development of SLE and additional drivers of differences between control groups.