Commentary by Lawrence D. Longo, MD

Abstract

The concept that the placenta and fetus, in concert with the mother, consists of a unit for hormonal synthesis and metabolism derived from the work of Diczfalusy et al. 1 Diczfalusy E. Das Verhalten von Choriongonadotropin und Oestrogenen in der menschlichen Placenta. 3. Symposium der Deutschen Gesellschaft für Endocrinologie, über probleme der fetalen Endocrinologie (in German). Berlin Heidelberg New York: Springer-Verlag;1970. p. 32-46. Google Scholar , 2 Diczfalusy E. Endocrine functions of the human fetus and placenta. Am J Obstet Gynecol. 1974; 119: 419-433 Abstract Full Text PDF Scopus (64) Google Scholar , 3 Mathur R.S. Archer D.F. Wiqvist N. Diczfalusy E. Quantitative assessment of the de novo sterol and steroid synthesis in the human foeto-placental unit: I, synthesis and secretion of cholesterol and cholesterol sulphate. Acta Endocrinol. 1970; 65: 663-674 PubMed Google Scholar , 4 van Leusden H.A. Siemerink M. Telegdy G. Diczfalusy E. Squalane and lanosterol synthesis in the foeto-placental unit of midgestation. Acta Endocrinol. 1971; 66: 711-719 PubMed Google Scholar In the case of steroid biosynthesis, by aromatization, the placenta converts 16α-hydroxy dehydroepiandrosterone sulfate that is made by the fetus from dehydroepiandrosterone sulfate into estriol. This is secreted into the maternal circulation and is the main estrogen metabolite that is excreted in the mother's urine. The fetus also can initiate the pathways for conversion of cholesterol to pregnenolone and on to dehydroepiandrosterone sulfate. Thus, the placenta, in concert with several fetal organs, plays a unique role in the regulation of steroid hormone production in pregnancy. Endocrine functions of the human fetoplacental unitAmerican Journal of Obstetrics & GynecologyVol. 193Issue 6Preview Full-Text PDF