FETAL TOXICITY OF ZIDOVUDINE (AZIDOTHYMIDINE) IN MACACA-NEMESTRINA - PRELIMINARY-OBSERVATIONS

The objective of this study was to determine the dam, fetal, and infan t toxicity of zidovudine (AZT) administered to pigtailed macaques duri ng pregnancy. Pregnant macaques were administered AZT (1.5 mg/kg/dose every 4 h) or water via gastric catheter throughout pregnancy. AZT con centration and hematological changes were monitored in the dam, and fe tal growth was monitored via ultrasound. Infant hematocrit was assesse d at birth, and the neurological, perceptual, and motor development of the offspring were assessed for 9 to 10 months. Twelve pregnancies we re brought to term. Mean plasma concentrations of AZT were comparable to those in human studies. Hemoglobin dropped significantly in pregnan t dams and remained low, whereas platelets increased during treatment but returned to normal before the end of the study. There were no sign ificant differences in any ultrasound measure of fetal growth, and AZT -exposed infants exhibited little behavioral delay or impairment. We p redict no significant toxic effects of prenatal AZT exposure at this d osage in humans.