Activated protein C resistance in cord blood from healthy and complicated newborns.

Objectives. Newborns are susceptible to thrombosis secondary to the immature hemostatic system and maternal and fetal complications. The contribution of activated protein C resistance (APCR) to thrombosis tendency has not yet been established. This study was conducted to investigate the effects of maternal and fetal complications on APCR levels. Methods. APCR levels were determined in cord blood from healthy term infants and compared with those in healthy preterm and complicated neonates as well as that in adult venous blood. Results. The mean value of APCR in cord blood from healthy term infants (166 ± 40 s) was not significantly different from that in adult venous blood (173 ± 40 s). No significant differences in the mean cord blood APCR values were observed between healthy term and preterm infants, infants with vaginal and cesarean delivery, infants from preeclamptic and non-eclamptic mothers, and infants with or without perinatal asphyxia. The activity levels of protein C, protein S, and antithrombin III were not significantly different between these groups except for lower levels in preterm babies. Conclusions. The level of APCR in cord blood is comparable to that in adults and not influenced by maternal and fetal complications. It appears that APCR does not contribute to the thrombotic tendency in newborns. [ABSTRACT FROM AUTHOR]