Sjögren's syndrome and pregnancy: a Portuguese case-control study

Pregnancy in patients with autoimmune disorders is associated with an increased risk of adverse outcomes. Sjögren's syndrome (SS) is one of the most common among autoimmune diseases. Presently data regarding the impact of SS on obstetric outcomes are scarce and inconclusive. This study aims to evaluate the impact of SS on maternal-fetal and neonatal outcomes compared with pregnancy outcomes in the general population.

A retrospective case-control study included 26 pregnancies in SS patients and a healthy control group (CG), followed in a Portuguese tertiary center, between 2015 and 2020. Baseline maternal data were collected, and maternal-fetal and neonatal outcomes were evaluated. Statistical analysis used SPSS 25.0, and a p-value of 0.05 was considered statistically significant.

All pregnancies occurred after the diagnosis of SS, with a mean exposure time between diagnosis and pregnancy of 4.92 ±2.78 years. In the SS group, the incidence of ANA, anti-Ro/SSA, and anti-La/SSB antibodies positivity was 80.8%, 61.5%, and 46.2%, respectively. Hydroxychloroquine (HCQ) was used in 57.7%.Miscarriage was significantly higher in the SS group (19.2% vs. 1.8%, p < 0.01). There was a higher prevalence of fetal growth restriction (OR 11.16, 95% CI: 0.96-129.26). Preterm delivery (9.5% vs. 5.6%, p = 0.503) and mean birth weight (2998.16 g vs. 3155.79 g, p = 0.178) did not differ significantly between the groups. In the SS group, admission to the neonatal intensive care unit (NICU) rate was increased (OR 71.67, 95% CI: 3.78-1357.16). Three pregnancies were complicated by congenital heart block (CHB) (14.3% vs. 0%, p = 0.015). In all cases, the diagnosis was performed during second trimester of pregnancy, and betamethasone was administered.

Women with SS had a significantly higher incidence of miscarriage, admission to NICU, and CHB than controls. Congenital heart block was the most critical condition that affects the offspring of mothers with SS. Successful pregnancy in the study group was possible with prenatal monitoring and a multidisciplinary approach.