Effects of vitamin E on the response of the fetal middle cerebral artery to the pressure test

Abstract

Objective. To examine the effects of the maternal administration of vitamin E on the vasoreactivity of the middle cerebral artery (MCA) in preterm fetuses.Study design. The vasoconstrictive response of the proximal segment of the MCA to brief and partial external occlusions of the umbilical vein (pressure test) was studied in 22 fetuses between 21 and 35 weeks of gestation, before, and 3 to 7 days after, the maternal administration of oral vitamin E (50 mg daily).Results. The vasoconstrictive activity of the MCA was eliminated in 15 fetuses (68.2%), unchanged in six (27.3%), and decreased in one (4.5%). In the latter seven cases, vasoconstriction of the proximal MCA in response to the pressure test was eliminated by increasing the vitamin E dosage to 100 mg/day.Conclusion. Vitamin E administered to the mothers had a pronounced effect on the proximal MCA reactivity in preterm fetuses.