Diazepam as an induction agent for caesarean section: a clinical and pharmacokinetic study of fetal drug exposure.

The transplacental passage and clinical effects of diazepam have been studied in 30 patients undergoing elective Caesarean section. General anaesthesia was induced with diazepam (20 mg) and maintained with nitrous oxide/oxygen. The time from completed intravenous injection of diazepam to clamping of the umbilical cord varied from 184 to 810 seconds. The concentrations of diazepam in serial blood samples obtained from the mothers, the umbilical cord and the newborn infants demonstrated that the transplacental passage of the drug was rapid and there was evidence that the distribution of the drug between the mother and the fetus came close to equilibrium. There was no consistent relation between Apgar scores and the extent of the fetal exposure to diazepam.