Outcomes and Influencing Factors of 126 Pregnancy Patients with Undifferentiated Connective Tissue Disease: A Real-world Prospective Study

Abstract

Abstract Background: Undifferentiated connective tissue disease (UCTD) patients have various clinical manifestations and tend to relapse during pregnancy. To analyze the factors influencing pregnancy outcomes, we observed the clinical characteristics of pregnant patients with UCTD and fetal abnormalities events, and compared the disease activity and differences in treatment between adverse pregnancy outcomes (APO) and normal pregnancy outcomes (NAPO). Methods: 126 pregnancies of 124 UCTD patients were enrolled from September 2018 to October 2021. Participants were divided into the non-aPL (no positive aPL or NC-aPL) group and aPL group. Subgroups (APO and NAPO group) were set according to the outcomes of pregnancy (failed pregnancy group and successful pregnancy group). The clinical characteristics, treatment, and the differences in pregnancy outcomes of each subgroup were analyzed. Results: The incidence of fetal Doppler ultrasound abnormalities events (DUAE) and APO was different in patients with different antibodies during pregnancy. In the previous pregnancy outcomes, failed pregnancies (especially the unexplained spontaneous abortion within 10 weeks, p=0.033) were more common in the aPL group (p=0.048). The usage of low dose asprin (LDA) combined with low molecular weight heparin (LMWH) in the aPL group was significantly higher than that in the non-aPL group (p<0.001, p=0.005, p<0.001, respectively). In APO group, the percentage of late fetal loss (≥10 weeks of gestation) in previous pregnancies was 34.4% (11/32)，compared to the 12.8% (12/94) in NAPO cases (p=0.006). Positive aβ2GPI-IgG and the incidence of thrombocytopenia were higher in APO than the NAPO group, that was 31.3%vs. 13.8% (p=0.028), 18.8% vs. 4.3%, (p=0.025), respectively. Multivariate analysis confirmed that the occurrence of late fetal loss in the past, positive aβ2GPI-IgG, and thrombocytopenia was involved as the risk factors of this oncoming APOs. Conclusion: UCTD patients, whether with aPLs or not, had high-risk pregnancies, and the live birth rate was around 90%. Anti-coagulations were more likely to be needed in patients with positive aPLs and can improve some DUAEs in pregnancies. The influencing factors of APO included the history of late fetal loss, positive aβ2GPI-IgG, and thrombocytopenia.