Systemic Lupus Erythematosus and Pregnancy: a Portuguese Case-Control Study

Pregnancy in systemic lupus erythematosus (SLE) patients is associated with an increased risk of adverse outcomes. During pregnancy, SLE patients have a higher rate of miscarriage, stillbirth, preterm delivery, fetal growth restriction, or hypertensive disorders of pregnancy. To date, only a few case-control studies were published with the purpose to evaluate the magnitude of risk associated with pregnancy in lupus patients. The aim of our study was to evaluate the maternal and fetal outcomes in a cohort of Portuguese SLE patients and to compare it with a group of healthy pregnant women. We conducted a retrospective case-control study that included all pregnant women with SLE managed at a Portuguese tertiary center, between 2010 and 2019. Pregnancy outcomes were compared between SLE patients and a group of matched healthy pregnant women. Baseline maternal data was collected, and maternal-fetal and neonatal outcomes were evaluated. One hundred twenty-four SLE pregnancies were included. Of the patients, 95.2% were in remission at conception. In 13.7% of cases, a lupus flare was diagnosed during gestation and in 17.9% in the postpartum period. The live birth rate was 84.6%, and the incidence of adverse outcomes was 40.3% (OR 2.64, 95% CI 1.67-4.18). Considering only patients in remission at conception, the presence of adverse outcomes remained significantly higher (36.8% vs. 20.3%, P < 0.01). Miscarriage rate was 15.3% (OR 5.85, 95% CI 2.57-13.34) and preterm delivery occurred in 12.4% of the patients (OR 1.72, 95% CI 0.83-3.57). Preeclampsia prevalence was higher in SLE patients (OR 3.92, 95% CI 1.32-11.57). In the SLE group, the newborn admission to an intensive care unit rate was increased (OR 4.99, 95% CI 1.47-16.90). No neonatal or maternal deaths were reported. In our study, pregnancy with SLE was associated with an increased incidence of adverse outcomes, even in a population of SLE patients with well-controlled disease.