Interrelationship of Estrogen Concentrations in the Maternal Circulation, Fetal Circulation and Maternal Urine in Late Pregnancy

The Effects of Estradiol and Estriol on Plasma Levels of Cortisol and Thyroid Hormone-Binding Globulins and on Aldosterone and Cortisol Secretion Rates in Man*

“…Estriol is quantitatively the most important metabolite of estradiol, being derived from this hormone and related precursors such as estrone, via a chemical transformation which is not reversible in vivo (1). Its production is known to increase extraordinarily in pregnancy, reaching levels of 60 mg/day or more during the last trimester of a normal human gestation (2,3).…”

Estrogen Pharmacology. I. The Influence of Estradiol and Estriol on Hepatic Disposal of Sulfobromophthalein (BSP) in Man*

“…From other studies in newborn and older children Vest (44) concluded that this delay was caused primarily by impairment of the secretory mechanism for the dye. The human fetus is exposed to extremely high levels [approximately 5 to 10 times maternal blood levels (45)] of estrogens, particularly estriol (34,36), near term. This fact, in light of the data reported here, suggests that impaired excretory capacity for BSP in the neonatal period may represent, in part, a residual effect of the intense hepatic exposure to these hormones in utero.…”

“…The observations reported here were made during a series of studies designed initially to examine the potential use of pharmacological amounts of natural estrogens as therapeutic or immunosuppressive (11)(12)(13) agents in man; the periods of estrogen administration therefore varied considerably from subj ect to subject. Liver function was examined in these patients by the following tests: per cent esterification of cholesterol, direct and indirect bilirubin, cephalin and thymol flocculations, thymol turbidity, prothrombin time, serum albumin and globulin, retention of BSP in plasma 45 Table II. BSP components in plasma obtained during comparable (i.e., plasma sampled at the same time in the same portion of the injection sequence) infusion periods were examined chromatographically (10,16,17) in 4 subjects as follows: 2 ml of plasma was extracted with approximately 10 ml acetone; the extract was dried in vacuo; the residue was redissolved in 0.5 ml distilled water, applied to a 5-cm strip on Whatman 1 paper, and that the chromatographic losses and optical densities of free and conjugated BSP were equal (17).…”

Human Growth

“…Estrogen secretion has been widely studied during pregnancy, but very few data are available on the secretion of estrogens by the fetal ovaries. It is evident that the fetal circulating estrogen levels are part of the placental production (Maner et al .. 1963;Laatikainen and Peltonen, 1974). In pregnant women, estrone sulfate, estradiol, and estriol plasma levels are in better correlation with fetal weight than with placental weight (Abdul-Karim et al, 1971;Loriaux et al.…”