Effects of chronic placental insufficiency on brain development in fetal sheep

Abstract

Clinical evidence has linked intrauterine compromise such as fetal hypoxemia to poor neurologic outcome in the newborn. In this study we examined the effects of inducing chronic fetal hypoxemia by impairment of placental function on brain development in fetal sheep. Placental insufficiency was induced from 120 to 140 d of gestation (term = 145-148 d) by injection of microspheres into the umbilical circulation in five fetal sheep. Fetal partial pressure of oxygen, PaO2, was reduced from 24.1 ± 0.5 mm Hg before embolization to 14.8 ± 0.4 mm Hg after embolization (p < 0.05). In another three fetuses a similar level of hypoxemia (PaO2, 13.8 ± 0.4 mm Hg) occurred spontaneously. At 140 d of gestat..