The transfer of cephradine across the placenta.

The transfer of maternally administered cephradine (1 g given intravenously) to the fetal circulation and amniotic fluid was investigated in 2 pregnant patients undergoing fetoscopy. Cephradine was detected in fetal serum between 23 and 72 minutes after injection and was present in therapeutic concentrations. Fetal serum levels appeared to peak at approximately 40-50 min. Amniotic fluid levels were rising during the sampling period of 97 min. Cephradine is transferred across the placenta and appears to be a suitable antibiotic for use in selected obstetric patients when penetration of the fetal compartment is desirable.