Autoantibodies in association with subchorionic haematoma in early pregnancy

OBJECTIVE: To explore the possible aetiology of subchorionic haematoma (SCH), especially its association with autoantibodies. MATERIAL AND METHODS: Early pregnant women who were detected SCH through ultrasonography were identified as the study group and those without SCH at comparable ages who visited the clinic at the same period of time were compared as the control group. Indexes of laboratory immune tests were compared between the two groups, as well as their pregnancy outcomes. RESULTS: A total of 97 SCH patients and 130 control cases were recruited in this study. A higher proportion of women was detected autoantibodies in the SCH group compared with control group (45.36% vs 21.54%, p = .000). Positive rates of ANA (24.74% vs 10.77%, p = .005) and laboratory antiphospholipid antibodies (ACL, anti-β2 GP1 or LA) (25.77% vs 11.54%, p = .005) showed significant differences between the two groups. The incidence of vaginal bleeding was significantly higher in the SCH group (43.30% vs 20.00%, p = .000). While the miscarriage rates were not significantly different (17.53% vs 15.38%, p = .666). And there were no significant differences in terms of preterm delivery rate, caesarean section rate, birth weight and pregnancy complications. Most SCHs (96.25%) were absorbed before 20th gestational week. In the SCH group, the average birth weight was significantly lower in women with autoantibodies. Clinical features and other pregnancy outcomes showed no significant differences between SCH patients with and without autoantibodies. CONCLUSIONS: The occurrence of SCH may be associated with autoantibodies. The pregnancy outcomes were comparable between women with and without SCH. KEY MESSAGES: 1. Subchorionic haematoma (SCH) is increasingly commonly observed in early pregnancy period, but the aetiology is uncertain and the clinical significance of SCH is controversial. 2. The occurrence of SCH may be associated with autoantibodies. 3. The pregnancy outcomes were not significantly different between women with and without SCH.