Myometrial blood flow in pregnancy measured with xenon-133.

Abstract

Fetal wellbeing is believed to be related to among other factors the maternal blood supply to the placenta. Previous efforts to measure the myometrial blood flow with sodium have not been wholly successful. Clinical research was done to measure the flow in 3rd-trimester pregnant women with Xenon an inert radioactive gas. The Xenon was deposited directly into the myometrium transabdominally. As with sodium preliminary results showed a marked scatter. The pattern however indicates a definite reduction in the blood flow in abnormal pregnancies. These included patients with preeclampsia placental insufficiency fetal death hypertension and subsequent fetal deaths during labor. The mean myometrial blood flow in normal pregnancies was between 12 and 13 ml/100 g/min with a range from 2-32 ml. The mean blood flow in abnormal pregnancies was 10 ml/100 g/min with a range from 2-26 ml. Possible reasons for the scatter of measurements are discussed. Radiation doses to the fetus and gonads through this method is only 5% of that received when the measurement was performed with sodium.