Passionate Births

What is amniotic fluid and what is it’s purpose? Also referred to as the “bag of waters”, the most pregnant women generally know about it is that about the time labor begins their amniotic sac will break, or be broken by their midwife or doctor, causing the start of the delivery process. They don’t however know what its purpose is during a pregnancy.

The amniotic fluid is the clear, slightly yellowish fluid within the amniotic sac that surrounds the baby in the uterus. The baby grows in this amniotic sac, surrounded by the amniotic fluid, as he learns to move his limbs, open his eyes and breathe. Amniotic fluid levels generally sit at approximately 800ml through most of the pregnancy, dropping slightly in most cases to about 600ml by the time a woman reaches the 40 week mark.

The amniotic fluid has many purposes. It helps to cushion hard blows and jolts to your belly to protect the baby and it allows your baby the freedom to move while permitting symmetrical musculoskeletal development. It also maintains an even temperature so that your baby does not get too hot or too cold, even if you are extremely hot or cold.

Amniotic fluid also helps your baby develop his lungs. While in the womb your baby practices breathing by breathing in and out the water in the amniotic sac. The baby swallows and inhales the amniotic fluid and replaces the volume in the amniotic sac by urinating and exhaling the liquid.

In some cases, a woman may have too much or too little amniotic fluid. Having too much is called polyhydramnios and having too little is called oligohydramnios. In either case, a woman might be watched more closely by her physician throughout her pregnancy.