Prevalence of plasma coagulation deficiencies and antiphospholipid antibodies positivity in the pediatric population of the Małopolska region: A single-center study from a pediatric hospital in Kraków.

Plasma coagulation disorders in children present with diverse and often subtle clinical manifestations, contributing to frequent underrecognition and delayed diagnosis. Data on the prevalence of bleeding disorders in Polish children are lacking. This study aimed to estimate the prevalence of plasma coagulation disorders and antiphospholipid antibodies positivity in 120 children aged 3-10 years from the Małopolska region. The study was conducted at a single pediatric center in Kraków, recruiting participants from hospital inpatients, outpatients, and primary care clinics. All children underwent clinical evaluation-including medical history, physical examination, and a standardized questionnaire-and were assigned to study or control groups. During the study, we assessed plasma coagulation factors I, II, V, VII, VIII, IX, X, XI, XII, and XIII, von Willebrand factor antigen (vWF:Ag), and von Willebrand factor ristocetin cofactor activity (vWF:RCo). Decreased activity of one or more coagulation factors (including Hageman anomaly) was identified in 28.33% of participants-33.33% in the study group and 23.33% in controls. A positive family history of bleeding significantly increased the likelihood of a coagulation disorder (OR 5.25, p = 0.002), whereas a personal bleeding history was not statistically significant. Routine screening assays (activated partial thromboplastin time [APTT] and prothrombin time [PT]) showed low sensitivity and did not reliably exclude mild hemostatic abnormalities. These findings highlight the high probability of underestimating bleeding disorder prevalence in children. Detailed family history remains a crucial diagnostic tool, while standard screening tests are insufficient. Population-based studies and educational initiatives are needed to improve recognition and diagnosis of pediatric hemostatic disorders.