A few trips to your OBGYN, and you’re sure to hear the word amniotic fluid. If you’ve never been pregnant before, you might have some questions like why do amniotic fluid levels during pregnancy matter? We’re here to tell you why this fluid matters so much during your pregnancy.
The truth is that amniotic fluid is mostly pee – seriously. The fluid starts to form inside of the amniotic sac after conception, and at that point, it’s mostly comprised of your body fluids. Then, around 11 weeks or a bit larger, your baby’s kidneys start to work and create urine.
Over time, those fluids build up, creating a cushion around your baby’s body. By the time that you’re about 20 weeks pregnant, the amniotic fluid in the sac is mostly urine.
The Purposes of Amniotic Fluid
Amniotic fluid is essential during pregnancy, and your uterus is filled with it. It has many important purposes, such as:
How Much Amniotic Fluid Should There Be?
The amniotic fluid in your uterus will continue to increase until you reach the 36th week of pregnancy. At that time, most women have around one quart of fluid. From that point, it starts to decrease.
At 20 weeks pregnant, most women have around 400 milliliters of amniotic fluid. That amount doubles to 800 milliliters by 28 weeks gestation. Then, it will stay at this level until 37 weeks, at which point it starts to go down gradually.
Typically, by the time that you give birth, there should be between 400 and 500 milliliters of fluid in the amniotic sac.
How Do Doctors Determine Amniotic Fluid?
Since the fluid levels are inside of your uterus, determining the amniotic fluid level can be a bit tricky. Doctors use a series of tests to check the levels and make sure that your baby is safe.
1. Non-Stress Tests
Non-stress tests, usually just called NSTs, are used to check a baby’s heartbeat while resting and moving. Mothers typically sit for a period attached to a monitor, which displays your baby’s heart rate and movements, along with the mother’s blood pressure and heart rate as well.
2. Biophysical Profiling
Commonly just called a BPP, this is an advanced ultrasound scan that detects your baby’s movement, muscle tone, breathing, and amniotic fluid levels. It might be followed up with a non-stress test.
3. Fetal Kick Counts
One of the earliest testing that you and your doctor can do to ensure your baby is healthy is to check fetal kick counts. It’s the time that it takes for your baby to kick a specific number of times.
4. Doppler Studies
Your doctor also can use simple doppler studies to check the sound waves following the flow of blood to your baby.
What Does the Color of Amniotic Fluid Mean?
The color of your amniotic fluid can tell you about the health of your pregnancy. Clear or tinted yellow amniotic fluid indicates a healthy pregnancy. A fluid that has a green or brown tint means that your baby passed a bowel movement inside of the womb, called meconium. The first bowel movement typically doesn’t come until after birth.
Passing meconium in the womb can be dangerous if it gets into your baby’s lungs through the amniotic fluid. Inhaling meconium can cause breathing problems called meconium aspiration syndrome.
Some babies who inhale meconium may require treatment right after birth to prevent an infection from developing in their lungs. Babies are closely monitored if meconium is present at birth.
Disorders Associated with Amniotic Fluid Level During Pregnancy
Complications associated with amniotic fluid comes from having too little or too much fluid in your uterus. Any fluid disorder can cause problems for a pregnant woman and her baby. Despite the disorder, most babies are born healthy.
What is Oligohydramnios?
If you have too little amniotic fluid, then you have oligohydramnios. This disorder occurs in around 4 percent of all pregnancies and 12 percent of post-date pregnancies. You will be diagnosed with oligohydramnios if your amniotic fluid levels are seen on an ultrasound measure less than 5 cm and a maximum vertical pocket is less than 2 cm.
This condition can happen in any trimester throughout your pregnancy, but it’s most concerning if it shows up in the first six months of pregnancy. That increases the risk of congenital disabilities, loss of the pregnancy, and preterm birth.
Oligohydramnios can be evident if you’re leaking fluid from a tear in the membranes. It also can occur with any of the following medical conditions.
What is Polyhydramnios?
Too much fluid is called polyhydramnios. This condition is less common, occurring in only one percent of all pregnancies. Women are diagnosed with polyhydramnios if their amniotic fluid levels are more than 24 cm, and the maximum vertical pocket is more than 8 cm.
Several fetal disorders put you at a higher risk of developing polyhydramnios, including:
Polyhydramnios can lead to some very severe complications in pregnancy, especially if you don’t closely watch your pregnancy. Mild cases can resolve themselves, but in severe case, mothers might need fluid reduced with amniocentesis or a medication called indomethacin.
Here are some of the potential complications of polyhydramnios.
How Do I Know if My Fluid is Leaking?
For some women, fluid leaks before their water breaks. Most of the time, women experience a leak rather than the gush that you associate with your water break. Only around 10% of women experience the dramatic gushes of fluid. Leaks or trickles are more common.
Let’s be honest; pregnant women can pee themselves as well, so you have to be able to determine if your fluid is leaking or if it’s urine. There is no shame in leaking some urine; you do have a baby doing gymnastics on your bladder. These things happen, but you probably want to save yourself the hassle of going to L&D.
Here is how you know if your fluid is leaking or if you leaked urine.
What is Premature Rupture of Membranes?
If your fluid leaks or ruptures before 37 weeks, which is considered a full-term pregnancy, it’s regarded as the premature rupture of membranes, mostly called PROM. It can have serious consequence for both the mother and the unborn child. PROM happens in only 2% of pregnancies.
You also can have premature rupture at term. That is when you’re 37 weeks pregnant or more and your fluid ruptures, but labor doesn’t start within six hours of the membrane rupturing.
It’s easy to forget how difficult pregnancy truly is, but our bodies create everything needed to protect and grow our babies. That includes amniotic fluid levels during pregnancy, which helps to protect your baby and encourage his growth and development. Amniotic fluid is one of the most critical factors in the health of you and your baby throughout these nine months ahead.