A comparison of plasma levels of progesterone, oestradiol, unconjugated oestriol and total oestriol with urinary total oestrogen levels in clinical obstetric practice

Summary: Plasma levels of progesterone (P), oestradiol (OE2), unconjugated oestriol (OE3) and total OE3 were measured in blood samples taken from patients with fetal growth retardation, pre-eclampsia and other complications of pregnancy. The levels were compared with the 24-hour urinary excretion levels of total oestrogen (OE) in these patients, and with the plasma levels found in 31 normal pregnant patients from whom blood samples were taken serially from 21 weeks gestation onwards. There was good correlation between plasma unconjugated and total OE, levels, and urinary OE levels (r = 0.77). In 12 patients with fetal growth retardation and no other abnormality, levels of all hormones were significantly lower than normal; unconjugated OE3, total OE3, and urinary OE levels were significantly less than 1 SD below the normal mean. In 22 patients with mild or moderate pre-eclampsia who were delivered of normal birth weight infants none of the hormone levels were significantly different from normal. In 12 patients with mild or moderate pre-eclampsia in association with fetal growth retardation OE2, unconjugated OE3 and urinary OE levels were significantly lower than normal, and total OE3 levels were significantly less than 1 SD below the normal mean. In 12 patients with severe pre-eclampsia, OE2, levels were significantly less than 1 SD below the normal mean and unconjugated OE3, total OE3, and urinary OE levels were significantly less than 2 SD below the normal mean. In studies of diurnal and day-to-day variation the coefficients of variation for P were respectively 12.7 per cent and 14.2 per cent, for OE2, 11 per cent and 12.7 per cent, for unconjugated OE3, 15.6 per cent and 14.1 per cent, and for total OE3, 15 per cent and 15.8 per cent. It was concluded that measurements of plasma total OE, and urinary OE were probably of comparable value and that the plasma estimation had much to commend it.