Fetal and Maternal Medicine Review

Table of Contents - 01 July 1991 - Volume 3, Issue 02  

Articles

Pathophysiology of amniotic fluid volume homoeostasis

Michael G Rossa1 c1 and M Gore Ervina1

a1 Harbor-UCLA Medical Center, UCLA School of Medicine, Torrance, USA

Human and ovine fetuses produce and absorb prodigious amounts of water and electrolytes daily. As will be described, fetal fluid exchange approximates to 300–400ml/kg per day near term. On a per kilogram basis, this is equivalent to an adult ingesting and secreting 15–20 litres per day. Upon delivery, the newborn rapidly adjusts to a much reduced rate of fluid exchange. In this respect, the fetus resembles an amphibian during development: an aquatic phase of in utero gestation and a comparatively arid state following delivery. Although the amphibian-like pattern of development may be partly an example of ‘ontogeny recapitulates phylogeny’, the remarkable volume of fetal fluid exchange suggests an important physiological role for amniotic fluid.

Correspondence:

c1 Michael G Ross MD, Associate Professor of Obstetrics and Gynecology, Harbor-UCLA Medical Center, UCLA School of Medicine, Torrance, CA 90509, USA.