EFFECT OF DELIVERY MODALITIES ON the physiologic inhibition system of coagulation in THE NEONATE.

Zanardo V1, Franzoi M1, Savio V1, Simioni P2

1 Department of Pediatrics, Padua, Italy

2 Department of Medical and Surgical Sciences, Padua, Italy


Objective: the stress associated with delivery may contribute to the maturation of the coagulation system. The aim of this study was to evaluate the influence of modality of delivery, spontaneous vaginal delivery or elective caesarean section, on the neonatal physiologic inhibition system of coagulation (PISC) factors, protein C, protein S and antithrombin III.

Methods: we studied 41 consecutive healthy newborns, 18 born after vaginal delivery (GA 39.7 0.8) and 23 after elective cesarean section (GA 38.5 0.7). The samples were collected in sodium citrate 1:9 from umbilical cord at birth, centrifuged and stored at -70 C until measurement. We tested ATIII activity, protein C antigen and activity (by chromogenic and coagulometric method), total amount and free form protein S antigen, and protein S activity.

Results: among PISC factors studied in cord blood of infants born after vaginal delivery, antigen protein C and antithrombin III were statistically higher (41,3 9,4 vs 33,9 7,2 % and 58,5 10,0 vs 48,4 12,7 %, respectively; p<.01 ), while free protein S was significantly lower (36,8 11,6 vs 46,4 12,5 %; p<.05) than newborns by cesarean section.

Conclusion: our data show that labor stress of vaginal delivery influences some PISC factors in cord blood. In newborns with coagulative disorders it is reasonable to consider different ranges in coagulative screening tests, related to delivery modality.