What is Amniotic Fluid Made Of?
Amniotic fluid is fascinating. Afterall, before our birth, we float in amniotic fluid, which provides temperature stability, cushioning, and a necessary presence within collapsed airways to help stimulate lung development. By the beginning of the second trimester there are 50 cc of fluid in the amniotic sac, and this fluid isn’t much different from the baby’s plasma, indicating an origin from secretions through the umbilical cord, membrane coverings of the placenta, and even the baby’s skin. By the 36th week there is usually around a liter of amniotic fluid, but by this time it is made up for the most part from fetal urine. The turnover of fluid is fairly rapid, with a build up from urine and a reabsorption from fetal swallowing being important dynamics in the amniotic fluid picture from hour to hour. Since the baby’s kidneys mature over the gestation, the amniotic fluid is more fetal urine-like later than it is when the kidneys are less mature. Also included in the amniotic fluid are
