Neutrophil extracellular traps in pregnancy complications

Neutrophil extracellular traps (NETs) are fibrous, web-like structures released by activated neutrophils that consist of decondensed chromatin DNA coated with antimicrobial granular proteins. These structures play a dual role in host defense and pathology by effectively entrapping and eliminating pathogens. Under normal physiological conditions during pregnancy, appropriately regulated NET formation at the maternal-fetal interface functions as a crucial antimicrobial defense mechanism. However, emerging evidence indicates that excessive NET formation or defective clearance is strongly linked to the pathogenesis of several pregnancy complications such as preeclampsia, gestational diabetes mellitus, preterm birth, recurrent pregnancy loss, systemic lupus erythematosus, and obstetric antiphospholipid syndrome. This review systematically examines the regulatory mechanisms and pathophysiological contributions of NETs to these pregnancy complications. This review further explores the potential therapeutic mechanisms of common obstetric medications-including aspirin, metformin, low molecular weight heparin, hydroxychloroquine, and vitamin D-which may exert beneficial effects by suppressing NET formation or enhancing NET clearance.