Abstract 328

Uterine "Contractures" (long lasting low amplitude episodes of myometrial activity (MA)) are present throughout pregnancy. In pregnant sheep spontaneous or oxytocin (OT) induced contractures are associated with lower fetal PO2 and increased fetal ACTH. To study potential consequences of changes in MA in primates, we infused 6 h OT pulses (OT group) daily for 14 days starting at day 148 of gestation to 5 pregnant baboons (180d, term age) and vehicle to 12 controls. Infants growth and neurobehavioral development were examined weekly till 6w of age. OT significantly increased MA in all experimental animals. There was no significant treatment effect on neonatal development of body weight, crown-rump and head circumference. Visual and motor maturity and state control (a measure for irritability and consolability) showed significant delay in OT group (p<0.05). These results are consistent with the hypothesis that prenatal factors, by virtue of changes in MA, may modify brain maturation in neonates.

This study was supported by NIH Grant HD28014.