Estrogen in pregnancy

W2. Warren, J, C., and Timberlake, C. E., Biosynthesis of estrogens in pregnancy Precursor role of plasma dehydroisoandrosterone. Obslet. Gynecol. 23, 689-698 (1964). 

Gas Chromatographic and Mass Spectro-metric Identification of Estrogens in Pregnancy Plasma... 

Gss Chromatographic Estimation of Estrogens in Pregnancy Urine Trans. Meet. Int. Study Group Steroid Hormones, 2nd, Rome 1965 21-25 (Pub. 1966) CA 68 36281k... 

This I5a-hydroxyIation during fetal life was conhrmed by the finding of an important quantity of 15a-hydroxylated estrogens in pregnancy urine (Knuppen et al., 1965, 1066a). 

The estrogens are a family of hormones synthesized in a variety of tissues. 17P-Estradiol is the primary estrogen of ovarian origin. In some species, estrone, synthesized in numerous tissues, is more abundant. In pregnancy, relatively more estriol is produced, and this comes from the placenta. The general pathway and the subcellular localization of the enzymes involved in the early steps of estradiol synthesis are the same as those involved in androgen biosynthesis. Features unique to the ovary are illustrated in Figure 42-7. 

Some women are rejecting conjugated equine estrogens in favor of preparations containing lower-potency estriol, a weak human estrogen produced in pregnancy and thought to be more protective of the... 

Important alterations in hepatic drug excretion and metabolism also occur. Estrogens in the amounts seen during pregnancy or used in oral contraceptive agents delay the clearance of sulfobromophthalein and reduce the flow of bile. The proportion of cholic acid in bile acids is increased while the proportion of chenodeoxycholic acid is decreased. These changes may be responsible for the observed increase in cholelithiasis associated with the use of these agents. 

Estriol is also produced by another pathway in the syncytiotrophoblast cells of the placenta DHEAS from fetal adrenal is converted to 16a-hydroxydehydroepiandrosterone sulfate in the fetal liver, followed by removal of the sulfated chain to produce 16a-hydroxy-dehydroepiandrosterone, which is then aromatized to estriol. Estriol is the predominant estrogen produced during pregnancy, and almost all of tiie estriol and estradiol produced by the placental syncytiotrophoblast enters the maternal circulation. By the 7th week of gestation, the placenta produces the majority of the estrogen in the maternal circulation. 

Estrogens should be avoided in individuals with current thrombophlebitis or thromboembolism, estrogen-depen-dent tumors, abnormal genital bleeding without a diagnosis, and pregnancy. They are also contraindicated in apparently healthy women if they have an earlier history of jaundice in pregnancy, hepatic disease, thromboembolism, or porphyria. 

A 32-year-old woman had psychotic symptoms of persecutory delusions, agitation, and auditory hallucinations a few days after her second injection of triptorelin (20). Her symptoms recurred after a pregnancy, suggesting that they were due to the rapid fall in estrogen in both instances. 

Early in pregnancy, glucose homeostasis is altered by the increasing levels of estrogen and progesterone, which lead to P-cell hyperplasia and an increased insulin response to a glucose load. During... 

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