The placental transfer of cefuroxime at parturition

Maternal and fetal serum concentrations of cefuroxime were determined at birth in 39 women who were given a single intravenous dose of either 750 mg or 1500 mg of cefuroxime before delivery. Mean serum cefuroxime concentrations in maternal venous and umbilical venous blood were dose dependent, being significantly higher after 1500 mg of cefuroxime (55.0 mg/l, 95% CI 33.4-80.9 and 19.5 mg/l, 95% CI 9.5-26.3, respectively) than after 750 mg (14.7 mg/l, 95% CI 10.5-21.1 and 8.8 mg/l 95% CI 5.8-9.4, respectively). Antibiotic concentration in maternal blood correlated with sampling time but a similar relationship was not found in cord blood. Fetal concentrations did not correlate with mode of delivery or initial maternal blood pressure. No relationship could be demonstrated between cefuroxime concentration in maternal or cord blood and maternal weight, maternal weight gain, birthweight of baby or volume of fluid infused prior to epidural anaesthesia. It is concluded that maternal and fetal concentrations likely to be effective for prophylaxis before delivery require a maternal dose of 1500 mg of cefuroxime and are independent of these physiological variables.