Determination of Placental Blood Flow by External Monitoring of 113mIn

Abstract

SummaryA simple and noninvasive technique was developed to evaluate the blood perfusion rate within human placenta. The method is based on monitoring the accumulation of the isotope 113mIn in the placental intervillous space using a single detector as a measuring device. The result was expressed as an accumulation index calculated from the tracer appearance curve. The In accumulation index was significantly lower in preeclamptic patients than in the controls, but with a marked overlapping. The In index was significantly correlated with the simultaneously recorded maternal minute volume, 24-hour estrogen excretion and birthweight. No correlation was found with the placental weight or Laakso’s perfusion index. Uterine contractions induced a significant decrease in the In index. The authors conclude that the In accumulation index can be used as an objective measure of the placental blood flow.

Ritodrine Hydrochloride Induced Cardiopulmonary and Placental Hemodynamic Changes in Normal and Hypertensive Late Pregnancy

“…The placental blood perfusion was assessed simultaneously with the radiocardiographic study by monitoring the accumulation of the tracer at the placental site using a radiation detector with a broad collimator directed to the central part of the placenta. The technique is described in detail previously (5,9). The heart rate and the systolic and diastolic blood pressures were recorded manually by a mercury manometer.…”

Acute effect of an antihypertensive drug, labetalol, on uteroplacental blood flow

“…In prc-eclampsia a mean reduction of 50% in uteroplacental blood flow has been observed (Olkkonen et al 1976;Lunell et al 1982) and in severe pre-eclampsia the impairment is even more pronounced. It would obviously he important to know whether a drug used to control a high blood pressure would further depress the uteroplacental blood Row.…”