Labor matters: thromboelastometry shows differences in newborn hemostasis

Background: Neonatal coagulation differs quantitatively from adult physiology, and conventional plasma-based tests provide limited functional insight into clot formation in newborns. Rotational thromboelastometry (ROTEM) enables dynamic, whole-blood assessment of clot initiation, propagation, and firmness. This study examined whether mode of delivery is associated with differences in early postnatal ROTEM profiles in term neonates. Methods: In this single-center cohort study, peripheral venous blood from 60 healthy term neonates (10 elective cesarean section, 24 intrapartum cesarean section, and 26 vaginal deliveries) was analyzed using ROTEM EXTEM and INTEM assays. Evaluated parameters included clotting time (CT), clot formation time (CFT), α-angle, clot amplitudes (A10–A30), maximum clot firmness (MCF), and maximum lysis (ML). Group differences were assessed using non-parametric tests, and independent associations were examined using multivariable regression models adjusting for neonatal and maternal variables. Results: Elective cesarean neonates demonstrated faster clot propagation and greater clot firmness compared with labor-exposed infants, reflected by shorter INTEM CFT, higher INTEM α-angles, and higher EXTEM and INTEM amplitudes. EXTEM MCF increased progressively from vaginal delivery through intrapartum cesarean to elective cesarean section. In contrast, CT and ML did not differ significantly between groups. Mode of delivery remained independently associated with parameters of clot propagation and firmness after multivariable adjustment. Conclusions: Mode of delivery, particularly exposure to labor. seems to be associated with differences in early postnatal ROTEM profiles in term neonates. These findings underscore the importance of perinatal context when interpreting viscoelastic coagulation testing in newborns and support development of delivery-specific reference intervals.