Perfusion of the intervillous space of the human placenta measured with99mtechnetium labelled human serum albumin

Abstract

The perfusion of the intervillous space of the human placenta was investigated with 99mTc-human serum albumin and external counting in 45 pregnant women between the 34th-38th wk of gestation. The pregnancy was normal in 34 women, while there was placental insufficiency in 11. Two variables were calculated from the placenta curve: the placenta flow index (PFI) and the mean transit time (.hivin.t) for plasma through the intervillous space. From double determinations, the coefficient of variation for PFI was calculated to 1.6%. For .hivin.t it was 20%. PFI was significantly higher in the controls than in the patients with placental dysfunction (P < 0.05). There was a significant correlation between PFI and .hivin.t (rs = -0.36, P < 0.05). The plasma estriol level and the PFI correlated significantly; correlation between .hivin.t and the plasma estriol level was not significant. The placenta flow index can be used to measure the physiological effect of a pharmacological treatment, bed rest or other treatments.