Abstract
Given the maternal hypercoagulability during pregnancy, thrombophilia may increase the risk of adverse pregnancy outcomes (APOs). This retrospective case-control study aimed to assess whether low-molecular-weight heparin (LMWH) could improve APOs in women with protein S (PS) deficiency. We selected 35 pregnant women who were considered for potential PS deficiency, and 70 healthy pregnant women were randomly selected as the control group. Two or more consecutive miscarriages were more frequent in pregnant women with PS deficiency than in the control group (12/35 vs. 4/70, P = 0.0001). Ten pregnant women with PS deficiency conceived by in vitro fertilization-embryo transfer (IVF-ET), which was significantly higher than the number of controls who conceived by IVF-ET (4/70, P = 0.0012). All 20 women in the LMWH-treated group (P = 0.001) had live births, which were significantly higher than that in the LMWH-untreated group (8/15, 53.3%). In the subgroup aged ⩽ 32 years of age, the number of live births in both groups was 7 (7/7, 100%) and 7 (7/12, 58.3%), respectively (P = 0.106). In conclusion, impediments to spontaneous conception and an elevated incidence of pregnancy loss may be associated with PS deficiency. Furthermore, the elevated live birth rate might be attributable to the administration of LMWH during gestation.