[Studies of aztreonam transfer into the fetus and amniotic fluid in early pregnancy].
The materno-fetal transfer of aztreonam by a single intravenous dose of 1 g was examined in 7 volunteer women undergoing induced abortion in early pregnancy and the following results were obtained. After administration of the drug, maternal blood levels at 15, 30, 60 and 120 minutes were 77.24 +/- 6.09 micrograms/ml (Mean +/- S.E.), 37.84 +/- 5.85 micrograms/ml, 25.62 +/- 3.15 micrograms/ml and 18.10 +/- 2.22 micrograms/ml, respectively. Amniotic fluid level of the drug was low in 3 cases, of which amniotic fluid levels were determined; 0.74 microgram/ml after 229 minutes, 0.83 microgram/ml after 280 minutes and 0.74 microgram/ml after 328 minutes. Fetal tissue concentration of the drug was below our detection limit at 120 minutes. Tissue levels of villus and decidua in 6 cases were also too low to be detectable between 89 and 328 minutes after injection.