Vaginal bleeding in the second trimester of pregnancy leading to preterm birth - a possible case of NETosis

Introduction: Preterm birth is a matter of significant concern due to its association with increased perinatal morbidity and mortality. While various causes of preterm birth have been identified, there are still unknown factors that pose challenges in terms of diagnostics and therapy. Case report: Presents COVID positive tertiparous women in second trimester, with an uneventful course of pregnancy, admitted at the Clinic with symptoms of abdominal pain, vaginal bleeding, fever, accompanied by vaginal discharge containing liquid blood and coagula. Notably, the patient expelled a cloth of necrotic tissue from the uterus, exhibiting visible accumulations of fibrin and abundant inflammatory infiltrates of neutrophils, suggesting NETosis as potential cause. These manifestations gradually led to the development of symptoms consistent with chorioamnionitis, ultimately resulting in a preterm birth at 27 weeks of gestation. Conclusion: In similar cases involving complicated pregnancies leading to preterm birth, it is important to consider NETosis as a potential differential diagnosis.