Amniotic Fluid

Amniotic fluid is essential in pregnancy. It is a water-like substance that is mostly made up of water until about 20 weeks. Starting at 20 weeks your baby will start to inhale or swallow the amniotic fluid then urinate it out. This keeps the amniotic fluid circulating. At 12 days after conception your body develops the amniotic sac, which holds the amniotic fluid and your baby. The amniotic fluid surrounds your baby. The greatest amount of amniotic fluid you will have is at 34 weeks where it will be around 800 mL. As your pregnancy continues the amount slowly decreases, at about 40 weeks you will have about 600 mL. Amniotic fluid is usually clear. It can have a pale yellow color like straw. If amniotic fluid is brown or green it means the baby has passed their first bowel movement which is called meconium. Amniotic fluid is odorless and is not sticky but has a very watery consistency.

Amniotic fluid has a very important role in pregnancy. A fetus cannot survive without amniotic fluid. Too little or too much amniotic fluid can cause complications. Amniotic fluid helps with fetal growth and development. It protects the fetus from infection, because it contains antibodies. It cushions the baby’s movements and helps the baby move easily to develop strong muscles and bones. Amniotic fluid prevents the umbilical cord from becoming compressed. It helps the baby develop the digestive and respiratory systems. It regulates the fetal body temperature. It also protects the baby from your movements, like falling or bonking your growing belly into things. The fluid contains nutrients, hormones, and antibodies that are essential for the baby.

Amniotic fluid can be measured with an ultrasound. The ultrasound tech will measure different pockets of fluid around the amniotic sac. From those measurements they will be able to measure the total volume of amniotic fluid.

Oligohydramnios is when you have too little amniotic fluid. This occurs in about 4% of all pregnancies. You may not have any symptoms when you have low amniotic fluid. You may notice that you are leaking amniotic fluid. This can be hard to tell if it is normal vaginal discharge or urine. Leaking amniotic fluid cannot be stopped unlike leaking of urine. The other thing to check for is if the fluid you are leaking is clear can be another clue if it is amniotic fluid. If you suspect you are leaking amniotic fluid it is best to be seen by your healthcare provider as soon as possible. Having too little amniotic fluid can be identified with an ultrasound and your amniotic fluid index measures less than 5 centimeters and the maximum vertical pocket measures less than 2 centimeters.

The main cause of oligohydramnios is leaking of amniotic fluid from a tear in the amniotic membranes. It can be identified if you are measuring small at a certain stage of pregnancy. Another sign of low amniotic fluid is low fetal movements, or kicks. You are at a higher risk of low amniotic fluid if you have had a previous pregnancy with growth restriction, if you have chronic high blood pressure, preeclampsia, diabetes, lupus, if you are delivering past your due date, if you have developed gestational diabetes, if there are problems with the placenta, or if you have pregnancy of multiples like twins or triplets.

Having low amniotic fluid is most dangerous in the first 6 months of pregnancy. It can lead to a miscarriage or physical deformities in the baby. Low amniotic fluid in the last trimester weeks 28-40 it can still cause complications. Complications can include umbilical cord compression, fetal growth restriction, respiratory issues, and a higher risk of having a C section. Treatment depends on when the low level of amniotic fluid occurs. You will be monitored more closely. Your doctor may suggest undergoing a nonstress test, biophysical profiling, fetal kick counts, and doppler studies. Depending on how far along you are it may be safer to induce labor than to try and keep the baby in. An amnioinfusion can be done to replace amniotic fluid. Bed rest may also be suggested.

Polyhydramnios is when you have too much amniotic fluid. Symptoms you may notice with too much amniotic fluid are swollen feet, breathlessness, or constipation. The amniotic fluid index measures more than 24 centimeters and the max vertical pocket is greater than 8 centimeters. It can be caused by gestational diabetes, carrying twins with transfusion syndrome, problems with the baby’s stomach, a condition affecting the baby’s swallowing, or issues with the placenta.

Complications that can occur due to polyhydramnios are preterm labor or birth, postpartum hemorrhage, fetus becomes too large, still birth, placental abruption, cord prolapse, or fetal malposition.

Mild cases may not be treated. Sometimes in mild cases it resolves on its own. You will be more closely monitored as your pregnancy progresses. Your doctor may suggest induction, bed rest, or draining a small amount of fluid from the amniotic sac.

Amniotic fluid is essential for the growth and health of your baby. It helps them practice breathing, and helps the kidneys learn to function by urinating out the amniotic fluid. Too much or too little amniotic fluid can cause complications in pregnancy. If you feel like you are leaking amniotic fluid at any point in your pregnancy, you will want to make your healthcare provider known.