Ethambutol in pregnancy--foetal exposure.

We report a case of miliary tuberculosis in a pregnant Jamaican woman in whom foetal exposure to ethambutol has been assessed. The mother received 15 mg/kg ethambutol as part of her antituberculosis therapy. Immediately after delivery, amniotic fluid, maternal, placental, and cord blood specimens were obtained and analysed for ethambutol concentrations. The levels were within the therapeutic range in all 4 samples. The concentrations indicate that the placenta is not a significant physiological barrier to the transfer of ethambutol to the foetus.