Pregnancy characteristics in patients with autoimmune diseases with different onset times and their relationship with pregnancy outcomes

BACKGROUND: Autoimmune diseases (AIDs) are highly prevalent among women of reproductive age and are associated with increased risks of adverse pregnancy outcomes (APOs). However, the correlation between different onset times of the diseases and pregnancy outcomes remains unclear. This study aimed to systematically analyze and compare the pregnancy characteristics and outcomes among women with AID, specifically focusing on those whose conditions manifest in childhood, before pregnancy in adulthood, or during pregnancy in adulthood. METHODS: A total of 348 pregnant women with AID from 2010 to 2024 were analyzed retrospectively. Patients were categorized based on three different onset times. Clinical features, laboratory characteristics and pregnancy outcomes were compared among groups. Logistic regression analyses were used to explore the relationship between the onset time of AIDs and APOs. RESULTS: Among the 348 pregnant patients, 39(11.2%) were childhood-onset cases, 215(61.8%) were cases diagnosed in adulthood before pregnancy and 94(27.0%) were occurring during pregnancy. Compared to pregnancy-onset group, pre-pregnancy-onset group showed a lower risk of fetal loss (OR = 0.410, 95% CI 0.201–0.835, P = 0.014). CONCLUSIONS: An increase in the incidence of adverse pregnancy outcomes was not observed in pregnant patients with autoimmune diseases as disease duration increased. Patients with AID onset during pregnancy in adulthood exhibited more aggressive disease manifestations and demonstrated a significantly higher incidence of APOs.