Significance of the estriol profile as an endogenous function test of the fetoplacental unit

Abstract

Oestriol profile represents a functional parameter of the foetal placental unit. Basing on the fact that maternal cortisol regulates oestriol production via a negative feedback action on foetal hypothalamus, relative low serum oestriol concentrations in the morning are compared with increasing oestriol concentrations in the evening, spaced out at short-time intervals, pointing to a dynamic oestriol production of the foetal placental unit. The mean oestriol concentration in the morning and maximum peak values in the evening were determined as criteria of the oestriol profile. In normal pregnancies (n = 74) the oestriol concentration in the morning increases from an average value of 8.0 ng/ml in the 32nd/33rd week to 11.6 ng/ml in the 40th/41st week of gestation. During the same period the peak values in the evening rise from 8.8 to 15.9 ng/ml. The mean cortisol concentrations in normal pregnancies (n = 49) from 32nd to 41st week are in the range of 333 +/- 88 ng/ml in the morning and 205 +/- 66 ng/ml in the evening. There is no significant difference between individual weeks. The predictive value of the oestriol profile was assessed regarding the foetal outcome of 55 high-risk pregnancies. 32 newborn infants exhibited intrauterine growth retardation with birth weights below the 10th and 5th percentile, respectively. In this group 6 patients exhibited low oestriol values in the morning, whereas 12 demonstrated a pathological profile in the evening. In 11 of 12 high-risk pregnancies exhibiting pathological oestriol profile growth, retardation of the newborn was found to be below the 5th percentile. Cortisol concentrations do not significantly differ between normal and high-risk pregnancies.(ABSTRACT TRUNCATED AT 250 WORDS)