Plasma haptoglobin levels in vacuum extracted neonates.

In order to examine the pathogenesis of neonatal hyperbilirubinemia associated with vacuum extraction, we have compared plasma haptoglobin and bilirubin levels and blood hematocrits of vacuum extracted neonates with those of newborns who underwent a normal vaginal delivery. Plasma haptoglobin and blood hematocrits of the 12 vacuum patients measured on the third day of life were significantly lower (21.7 +/- 5.3 vs. 46.5 +/- 7.5 mg%; p value less than 0.01 and 52.3 +/- 1.3 vs. 59.7 +/- 1.8%; p value less than 0.005, respectively) than the 12 control patients (values are mean +/- SEM). This trend was apparent whether or not cephalhematoma was present after vacuum extraction: However, the mean bilirubin level was significantly higher than the controls only when cephalhematoma was present. Those results suggest that the higher incidence of neonatal hyperbilirubinemia previously observed after vacuum extraction, is the result of an increased hemolysis of blood sequestered in scalp lesions. Since evidence for enhanced RBC destruction has been demonstrated whether or not cephalhematoma was present, the possibility of hyperbilirubinemia should be anticipated in any case of vacuum delivery.