Abstract： Objective:To explore the clinical characteristics of pregnancy complicated by primary Sj?gren's syndrome (pSS) and the related factors of adverse outcomes in pregnant women with pSS.Methods:A retrospective analysis was conducted on the clinical data of 32 pregnancies complicated by pSS treated in the Department of Obstetrics at the Third Affiliated Hospital of Guangzhou Medical University from February 2017 to August 2022. The patients were divided into two groups according to whether they had perinatal adverse outcomes: an adverse outcome group ( n=20) and a favorable outcome group ( n=12). The clinical characteristics of the two groups were compared with two independant sample t-test, Mann-Whitney U test, and Fisher's exact test, and multivariate logistic regression analysis was used to analyze the related factors of adverse outcomes in pregnant women with pSS. Results:(1) The average maternal age of the 32 pSS pregnancies was (32.9±4.6) years, the pre-pregnancy body mass index was (21.1±3.8) kg/m 2, and the median gestational age at delivery was 37.8 (35.4-38.5) weeks. There were 18 women (56.3%, 18/32) were diagnosed before pregnancy and 14 women (43.7%, 14/32) during pregnancy. Out of the 32 pregnancies, 25 (79.1%, 25/32) received therapy with glucocorticoids and/or hydroxychloroquine during pregnancy, whereas seven (21.9%, 7/32) had no medication during pregnancy. (2) The main adverse maternal outcomes included oligohydramnios (25%, 8/32), hypertensive disorder of pregnancy (18.8%, 6/32), preterm birth (18.8%, 6/32), fetal growth restriction (15.6%, 5/32), miscarriage (12.5%, 4/32), gestational diabetes mellitus (9.4%, 3/32), and postpartum hemorrhage (3.1%, 1/32). (3) Adverse neonatal outcomes included low birth weight infants in seven cases (25.0%, 7/28), neonatal asphyxia in seven cases (25.0%, 7/28), and two cases of congenital heart block (7.1%, 2/28). (4) The rate of diagnosis before pregnancy in the favorable outcome group was higher than the adverse outcome group [10/12 vs. 40.0%(8/20), Fisher's exact test, P=0.028]. There were no significant differences between the two groups concerning maternal age, pre-pregnancy BMI, weight gain during pregnancy, parity, rates of positivity for autoantibodies (antinuclear antibody, Sj?gren-specific antibody A, Sj?gren-specific antibody B, anti-Ro-52), and proportion of drug treatment (glucocorticoids, hydroxychloroquine) (all P>0.05). (5) Multivariate logistic regression analysis showed that diagnosis before pregnancy ( OR=0.02, 95% CI: 0.00-0.62, P=0.024) and positive Sj?gren-specific antibody B ( OR=0.01,95% CI: 0.00-0.75, P=0.038) were the protective factors. Conclusions:The clinical manifestations of pSS among pregnant women are varied and atypical,often with insidious onset. For pregnant women with pSS, being diagnosed before pregnancy, positive Sj?gren-specific antibody B may reduce adverse outcomes. It is important to address pre-pregnancy examination, early diagnosis and timely intervention to reduce the occurrence of adverse outcomes in pregnant women with pSS.