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

Plasma progesterone levels in normal and abnormal early human pregnancy

Radwanska E et al., 1978 · Fertil Steril

Blood-progesterone and urinary pregnanediol and oestrogens in foetal death from severe pre-eclampsia

Coyle MG et al., 1962 · Lancet

Plasma estrone, estradiol, estriol, progesterone, and 17-hydroxyprogesterone in human pregnancy. I. Normal pregnancy

Tulchinsky D et al., 1972 · Am J Obstet Gynecol

To describe normal relationships between the various plasma unconjugated estrogens and progesterone during the second half of human pregnancy, the plasma concentrations of progesterone, 17-hydroxyprogesterone (17-OHP), and unconjugated estrone (E1), estradiol (E2), and estriol (E3) were measured in 126-310 normal women. Progesterone and unconjugated E1, E2, and E3 increased gradually throughout later pregnancy; 17-OHP increased only after the thirty-third week. At term the mean value of progesterone was 9 times higher than that 17-OHP. Throughout pregnancy the mean value of E2 was higher than that of E1 or E3. During the second half of pregnancy the ratios of progesterone to estradiol and estriol and of estradiol to estriol remained unchanged, indicating no preferential increase of plasma concentration of maternal or fetal hormones.

Plasma progesterone levels in normal and abnormal pregnancies

Lindberg BS et al., 1974 · Acta Obstet Gynecol Scand

Plasma progesterone levels were estimated by competitive protein binding in 815 samples from healthy pregnant women with uncomplicated pregnancies. This series includes 32 patients who were followed serially throughout pregnancy. The mean level increased from 47 ng/ml in week 22 to 148 ng/ml in week 41. The spread was large. Individual patients showed very large variations between two consecutive weeks. Diurnal variations were examined in 7 patients and short-time variations during one hour in 5 patients. Large but non-systematic variations were found in most cases. The maximal difference between values observed over a 24-hour-period was 123 ng/ml and during one hour 150 ng/ml. Plasma progesterone levels were studied in 87 cases of toxemia of pregnancy, 6 cases of hypertension, 54 cases of Rh-immunization, 37 cases of diabetes and 5 cases of fetal growth retardation of unknown origin. The results indicate that no constant changes occur in plasma progesterone levels in these groups or in cases of impending fetal death. As the normal limits are very wide, the intraindividual variations large, and the progesterone values in high risk pregnancies are inconclusive, plasma progesterone estimates during the latter part of pregnancy seem to be of limited value. During human pregnancy large amounts of progesterone are produced by the placenta (1, 14). The production rate during the third trimester lies between 200 and 300 mg/day (9). Part of the progesterone produced is metabolized to pregnanediol and excreted in the urine as the 3-glucuronidate (16). The percentage of conversion to pregnanediol seems to vary with the stage of gestation and is influenced by pathological alterations in risk pregnancies (2, 5). Large day to day variations in the urinary pregnanediol levels have been found. It is thus hardly surprising that the clinical value of serial determinations of urinary pregnanediol in late pregnancy has been limited. Recently useful methods for the assay of progesterone in plasma have been developed and applied to physiological and clinical studies. A number of reports dealing with the prognostic value of progesterone determinations in complicated pregnancies have been published (8, 12, 17). The number of cases investigated is, however, small and the results are, in many respects, inconclusive. The aim of the present investigation was to determine the normal limits during the latter half of uncomplicated pregnancies, circadian and short-time variations, and to evaluate the prognostic value of progesterone determinations in plasma in high risk pregnancies.

Plasma progesterone, serum estriol and plasma HPL determinations during the last trimester to detect changes before spontaneous labor. Comparison of progesterone assay using RIA and CPB

Ottesen B et al., 1979 · Acta Obstet Gynecol Scand

Conflicting results have been published regarding changes in plasma progesterone during the last trimester of pregnancy. Some have demonstrated a fall in plasma progesterone before labor, and this has been taken as a possible explanation of the onset of labor. It has been suggested that the various results could be due to differences in methods for progesterone determination. In this study the progesterone levels were determined by both RIA and CPB. In 11 women the plasma progesterone, human placenta lactogen, and serum estriol were measured weekly during the last trimester of normal pregnancies and immediately after delivery. All samples were analysed radioimmunologically. In order to compare the radioimmunoassay and competitive protein binding techniques (RIA and CPB), the progesterone levels were determined by both methods. This was also done for 80 successive plasma progesterone routine samples drawn from women who were not pregnant or who were in the early stages of pregnancy. Both methods showed a significant rise in the plasma progesterone level during the last 6 weeks before spontaneous labor. However, the values obtained were lower when assayed by CPB than by RIA, presumably because of a higher specificity and a cross reaction in RIA. Serum estriol exhibited increasing values throughout pregnancy, but without a significant rise during the last few weeks. Plasma HPL settled at a constant level during the last few weeks before labor.