Association of Anti‐Annexin A5 Antibody With Pregnancy Outcomes: A Cohort Study

ABSTRACT Objective This study aims to evaluate the correlation between anti‐annexin A5 (aANXA5) antibody in the blood and pregnancy outcomes . Methods This study is a retrospective cohort study based on singleton pregnancies of the Third Affiliated Hospital of Wenzhou Medical University from May 2018 to December 2022. Baseline characteristics were collected from all participants. Logistic regression and interaction effect analyses were utilized to examine the risk impact of aANXA5 on pregnancy complications, adjusting for age, BMI, abortion, ANA, and aCL. Restricted cubic spline (RCS) and threshold effect analysis were applied to explore the relationship between aANXA5 levels and preterm birth (PTB), as well as pregnancy‐induced hypertension (PIH). Results The study included 501 participants, with 51 (10.2%) testing positive for aANXA5 and 450 (89.8%) testing negative. The aANXA5 positive group exhibited higher rates of ANA and antibodies to thyroglobulin (TGAb), along with increased incidences of PTB and PIH. Positive aANXA5 status was independently linked to an elevated risk of PTB (OR: 2.53, 95% CI: 1.30–4.94) and PIH (OR: 4.23, 95% CI: 1.54–11.62). Subsequent subgroup analysis indicated no significant interaction between the groups ( p > 0.05). Threshold analysis revealed that the OR for PTB was 1.20 (95% CI: 1.03–1.39) in participants with aANXA5 levels ≥ 32.77 ng/mL, and the OR for PIH was 1.62 (95% CI: 1.15–2.28) in those with aANXA5 levels ≥ 33.20 ng/mL. Conclusion AANXA5 is independently associated with an increased risk of PTB and PIH. The identified optimal predictive cutoff values are 32.77 ng/mL for PTB and 33.20 ng/mL for PIH.