FETAL CARDIORESPIRATORY AND NEUROBEHAVIORAL RESPONSE TO ZIDOVUDINE (AZT) IN THE BABOON

OBJECTIVE: To evaluate the effects of intravenous of zidovudine (AZT) at a nose and duration of infusion comparable to that used clinically on parameters reflective of fetal well-being. METHODS: Thirteen chroni cally instrumented noninfected baboons were monitored during intraveno us infusions of AZT. Fetal cardiorespiratory activity and neurobehavio ral function were assessed with 4-48-hour infusion of AZT to ten mothe rs (0.5-2.1 mg/kg per hour) and three fetuses (2-6 mg/h), which result ed in fetal plasma concentrations of AZT of 194-3100 ng/ml. RESULTS: N o significant differences were found in the mean values in control per iods, before and after infusion with values during infusion for parame ters of fetal heart rate and rate variability (n = 7), breathing activ ity (n = 8), electroencephalographic activity (n = 8), and behavioral state (n = 7). No correlations were found with drug level. CONCLUSIONS : The absence of associations between exposure of the fetal baboon to AZT and changes in parameters reflective of fetal condition suggests t hat comparable exposure of the human fetus during intravenous infusion of drug would not confound clinical monitoring used to assess fetal w ell-being. These findings supplement conclusions from clinical researc h in support of U.S. Public Health Service recommendations that intrap artum fetal monitoring be performed as clinically indicated, not speci fically because pregnant patients are treated with intravenous AZT. Co pyright (C) 1997 by the Society for Gynecologic Investigation.