Amniotic Fluid

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Related to Amniotic Fluid: placenta, Amniotic fluid embolism

amniotic fluid

[¦am·nē¦äd·ik ′flü·əd]
A substance that fills the amnion to protect the embryo from desiccation and shock.

Amniotic Fluid


fluid that surrounds the fetus of higher vertebrate animals (including man) while developing in the mother. It fills the gestation sac formed by the fetal membranes. The Russian scientist K. N. Vinogradov found in 1871 that this fluid is produced by the secretion of the amnion. It is a light transparent liquid containing albumin, fat, sugar, sodium chloride, urea, hormones, and radioactive substances, which contribute to the production of energy for rapid growth and development of the fetus. The amount of amniotic fluid varies with the time of pregnancy—from 300 milliliters at the beginning to 1.5 liters at the end.

Amniotic fluid prevents the skin of the fetus and the amnion from coming into contact and fusing; enables the fetus to move actively, which is necessary for its development; protects the umbilical cord and placenta against pressure from the large parts of the fetus; influences the position of the fetus and the location of its parts; protects the fetus against external injuries; helps to open the mouth of the uterus during childbirth; and contributes to the distensibility of the uterus and normal course of labor. In severe gestational toxicoses, cardiovascular diseases, diabetes mellitus, and so forth hydramnios, or excess of amniotic fluid (more than 2 liters), may arise and cause extreme distension and attenuation of the uterine walls, which can sometimes lead to an abortion or incorrect position of the fetus. An insufficiency of amniotic fluid owing to inadequate secretory activity of the amnion prevents the fetus from developing normally. A premature effusion of amniotic fluid may result in an abortion.


Kuntsevich, A. N. Okoloplodnye vody kak toniziruiushchee i lechebnoe sredstvo v akusherstve. [Ivanovo] 1937.
Vinogradova, S. P. O biologicheskom znachenii okoloplodnykh vod. Kiev, 1928.


References in periodicals archive ?
This method was further developed for prenatal diagnosis by measuring the sterols in amniotic fluid (3-9) or chorionic villus cells (10, 11).
The current approach to the detection of infection and/or inflammation in the amniotic fluid includes other tests that are routinely performed for the analysis of cerebrospinal fluid in all hospitals in the United States.
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Although BPA concentrations in amniotic fluid at 15-18 weeks' gestation have been shown to be five times those in the serum of pregnant and nonpregnant women--suggesting possible accumulation in the embryo this could not be confirmed through animal experiments.
The test, which involves inserting a needle into the abdomen to collect a sample of amniotic fluid, is recommended for women over 35, but Oasay said the presence of retardation in her family's background made the test important even before she got into the higher-risk age range.
The hospital denies that the amniotic fluid sample was mishandled or mislabeled, and the laboratory stands by the accuracy of its results.
About a week before the birth of each mouse, the researchers, using a novel form of gene therapy somewhat like amniocentesis, pierced the mother's amniotic sac and injected into the amniotic fluid genetically engineered viruses harboring the therapeutic gene.