Abstract
OBJECTIVE: The objective is to examine the correlation of anti-phosphatidylethanolamine (aPE) antibodies with premature birth. Premature birth is an important risk factor for infant mortality and subsequent development of mental, metabolic and cardiovascular diseases. However, the risk factors associated with preterm birth are not well understood. aPE antibodies are an anti-phospholipid autoantibody that is thought to be a factor in pathological pregnancy. However, aPE antibodies have not been included in the classification criteria for antiphospholipid syndrome. Therefore, we aimed to check the clinical significance of aPE antibodies in association with premature birth. DESIGN: We conducted a retrospective analysis of 442 pregnant women who had experienced at least one unexplained miscarriage and were tested for aPE antibodies and compared their clinical characteristics, coagulation indicators, immune biomarkers and pregnancy outcomes. Logistic regression analysis was employed to identify factors associated with premature birth. SETTING: Ruian City, Wenzhou, Zhejiang Province, China. PARTICIPANTS: A total of 442 patients with ultrasound-confirmed intrauterine pregnancy from the Third Affiliated Hospital of Wenzhou Medical University between May 2018 and December 2022 were retrospectively selected and included in the study. The inclusion criteria were as follows: having been tested for aPE and having experienced at least one unexplained miscarriage. The exclusion criteria were as follows: (a) incomplete clinical records, (b) being positive for typical antiphospholipid antibodies (aPL, aβ2-GP1 and LA), (c) hormone or metabolic disorder, (d) lost to follow-up, (e) known clinical autoimmune diseases, (f) severe reproductive system infection or malformation, (g) fetal loss: pregnancy loss before 24 weeks and (h) multiple pregnancy. In this study, preterm birth was defined as birth before 37 weeks. PRIMARY AND SECONDARY OUTCOME MEASURES: We enrolled 442 patients in our study: 60 pregnancies with premature birth and 382 pregnancies with term birth. RESULTS: Our findings revealed that among the 442 participants, 13.6% had a premature birth (<37 weeks). Elevated aPE antibody levels were independently associated with an increased risk of premature birth. Multivariate logistic regression showed that the OR for premature birth was significant across all models, with the highest OR observed in the fully adjusted model (OR=1.19; 95% CI: 1.12 to 1.27). No significant interactions were found in any subgroups after stratifying by age, body mass index, previous miscarriage, complement C3, homocysteine and fibrinogen. The analysis revealed a linear relationship between aPE antibodies and premature birth. CONCLUSION: Our findings suggest that aPE antibodies may be independent risk factors for premature birth.