[The effect of diazepam on neonatal neurobehavioral response]

Diazepam was administered I.V. in 10mg doses to 26 normal women in labor, and its blood concentration in the mother and newborn, Apgar score and acid-base status in umbilical cord blood were determined immediately after delivery. The effect of diazepam on the neurobehavioral response of the newborn was evaluated by using the early neonatal neurobehavioral scale (ENNS) by Scanlon et al. Diazepam was swiftly transported into fetal blood through the placenta, to attain a higher blood concentration in the umbilical vein (UV) than in the maternal vein (MV) at 1-2 min after administration. The UV blood concentration of diazepam was always higher than the MV blood concentration, irrespective of the time between administration and delivery. A comparison of the blood concentration in the umbilical vein and the umbilical artery (UA), showed that the UV blood concentration was higher until 30 min after administration, but roughly eqalled the UA blood concentration thereafter. In terms of mean values in all the patients, the blood concentration in the UV (506 +/- 245 ng/ml) was significantly higher than that in the MV (350 +/- 204 ng/ml) or the UA (394 +/- 142 ng/ml). No significant difference was detected between the diazepam-treated group and the control in respect to the Apgar score, acid-base status in cord blood, neonatal serum bilirubin or time required for restration of the newborn to body weight at birth. The ENNS test showed suppression of nearly all the response immediately after birth, with suppression of response to pinprick, rooting response and sucking response persisting until 8 hr after birth.(ABSTRACT TRUNCATED AT 250 WORDS)