MYOCARDIAL AND CEREBRAL OXYGEN DELIVERY ARE NOT ADVERSELY AFFECTED BYCOCAINE ADMINISTRATION TO EARLY-GESTATION FETAL SHEEP

OBJECTIVES: Cocaine administration to near-term pregnant sheep causes fetal hypoxemia, but oxygen delivery to the heart and brain are preser ved because of increased blood flow. We hypothesized that cocaine admi nistration during earlier fetal gestation impairs oxygen delivery to t he heart and brain. STUDY DESIGN: Ten pregnant ewes and fetuses at 0.7 term gestation underwent surgical instrumentation. After 48 hours of recovery fetal blood pressure, heart rate, cerebral and myocardial blo od flow, and arterial oxygen content were determined before and during cocaine administration to the ewe. RESULTS: Fetal hypoxemia was not n oted in these animals. Fetal myocardial blood flow increased from 220 +/- 100 ml per 100 gm per minute to 349 +/- 183 ml per 100 gm per minu te (p = 0.03), and oxygen delivery increased from 16 +/- 5 ml of oxyge n per 100 gm per minute to 22 +/- 7 ml of oxygen per 100 gm per minute (p = 0.02). Fetal cerebral blood flow and oxygen delivery remained un changed. CONCLUSION: Cerebral and myocardial oxygen delivery are unimp eded by maternal cocaine administration in 0.7 term gestation ovine fe tuses.