Pregnancy Outcomes in Patients with Systemic Lupus Erythematosus Compared to a High-Risk Tertiary Cohort and to Standard Population from the Austrian Birth Registry

Introduction: Women with systemic lupus erythematosus (SLE) have a higher risk for fetal and maternal complications. We aimed to investigate maternal and fetal complications in pregnant women with SLE compared to a high-risk pregnancy cohort (HR) from a tertiary university center and a standard-risk general population (SR) from the Austrian Birth Registry. Material and Methods: In this retrospective data analysis, we compared the incidence of fetal/neonatal and maternal complications of pregnancies and deliveries of women with SLE to age, body mass index and delivery date-matched high-risk pregnancies from the same department, a progressive tertiary obstetric center and to a group of women, who represent pregnancies with standard obstetric risk from the Austrian Birth Registry. Results: One hundred women with SLE were compared to 300 women with high-risk pregnancies and 207 039 women with standard-risk pregnancies. The incidence of composite maternal complications (preeclampsia, Hemolysis, Elevated Liver enzymes and Low Platelets [HELLP] syndrome, pregnancy-related hypertension, gestational diabetes mellitus, maternal death, thromboembolic events) was significantly higher in the SLE as compared to the SR group (28% vs. 6.28% SLE vs. SR, p = 0.001). There was no difference between the SLE and the HR groups (28% vs. 29.6% SLE vs. HR group, p = 0.80). The incidence of composite fetal complications (preterm birth before 37 weeks of gestation, stillbirths, birth weight less than 2500 g, fetal growth restriction, large for gestational age, admission to neonatal intensive care unit, 5-min Apgar <7) was also higher in the SLE than in the SR group (55% vs. 25.54% SLE vs. SR p < 0.001) while the higher incidence of adverse fetal outcome was detected in the HR than in the SLE group (55% vs. 75% SLE vs. HR group, p = 0.0005). Conclusions: Although composite fetal risk is higher in the SLE group than in the general population, it is still significantly lower as compared to high-risk pregnant women at a tertiary obstetric center. Prepregnancy counseling of women with SLE should put fetal and maternal risk in perspective, not only in relation to healthy, low risk cohorts, but also compared to mixed HR populations.