Association between pregnancy outcomes prior to diagnosis and clinical characteristics following diagnosis in patients with systemic sclerosis.

objectiveTo investigate the clinical characteristics of pregnancy outcomes in patients with systemic sclerosis (SSc) prior to diagnosis and their association with clinical phenotypes following diagnosis.

methodsA retrospective analysis was conducted on data from 106 female SSc patients treated at Guizhou Medical University Affiliated Hospital between November 2019 and August 2025. All patients had experienced at least one pregnancy prior to diagnosis. Patients were categorised into an adverse pregnancy outcomes (APOs) group (n = 21) and a non-APOs group (n = 85) based on the occurrence of adverse pregnancy outcomes. Clinical manifestations, laboratory parameters, and differences in clinical subtypes were compared between groups. Multivariate logistic regression analysed independent factors for APOs.

resultsAmong 106 SSc patients, 19.81% (21/106) had a history of APOs, with spontaneous abortion being the most common (12.26%, 13/106). Univariate analysis revealed that patients with a history of APOs demonstrated significantly higher post-diagnosis anti-RNA polymerase III antibody positivity rates (42.86% vs 8.24%, P < 0.001), IgG levels (18.10 g/L vs 10.20 g/L, P = 0.002), and proportions of sine scleroderma (ssSSc) (23.81% vs 5.88%, P = 0.036) compared to those without such history. Multivariate regression analysis indicated that post-diagnosis detection of anti-RNA polymerase III antibodies (OR = 6.441, 95% CI: 1.794-23.133, P = 0.004), elevated IgG levels (OR = 1.104, 95% CI: 1.025-1.190, P = 0.009), and ssSSc (OR = 5.072, 95% CI: 1.044-24.637, P = 0.044) were independently associated with a history of APOs in SSc patients.

conclusionAmong women with SSc, a history of APOs prior to diagnosis was significantly associated with anti-RNA polymerase III antibody positivity, elevated IgG levels, and the ssSSc phenotype at the time of diagnosis. Key Points • This study investigated the association between adverse pregnancy outcomes occurring before the diagnosis of SSc and immunological as well as clinical phenotypes at the time of diagnosis. • The findings suggest that anti-RNA polymerase III antibody positivity, elevated IgG levels, and the ssSSc clinical subtype were significantly associated with patients' prior adverse pregnancy history. • These results highlight the possibility of a prolonged subclinical evolution in autoimmune diseases and offer a basis for future prospective cohort studies and improved risk stratification in high-risk populations.