You are waiting for a baby and you begin wondering about all these new pregnancy terms that you start hearing all around you. “What is amniotic fluid?” or “What does amniotic fluid look like?” are some of the questions that arise in your mind.
Table of Contents
- 1 What Is Amniotic Fluid?
- 2 Where Does Amniotic Fluid Come From?
- 3 What Does Amniotic Fluid Smell Like?
- 4 What Is the Role of Amniotic Fluid?
- 5 Can You Leak Amniotic Fluid?
- 6 What Are the Causes of Leaking Amniotic Fluid?
- 7 What Does It Feel Like When Your Water Breaks?
- 8 PH Level of Amniotic Fluid & How Much Liquid Is Normal?
- 9 Oligohydramnios or Oligoamnios (Not Enough Amniotic Fluid)
- 10 Polyhydramnios (Excess of Amniotic Liquid)
What Is Amniotic Fluid?
The baby grows and develops in the uterus in an amniotic sac containing the amniotic fluid, a clear liquid that has no color or smell, and is completely sterile. The amniotic liquid is part of the child`s life support system. This protects the baby and contributes in the development of muscles, limbs, lungs and digestive system.
The amniotic liquid is produced shortly after the formation of amniotic sac, at around 12 days from conception. This liquid contains mostly water, but also urine, nutrients (proteins, lipids, carbs, phospholipids, urea), hormones and antibodies. The water is produced by the mother`s organism, and then (around the week 20 of pregnancy) the fetal urine becomes the primary substance.
The amniotic cavity is filled with amniotic liquid the first few weeks of pregnancy. An excess or lack of sufficient amniotic fluid leads to an increased risk for both the mother and baby. Its volume increases along with the fetus`s growth, reaching its maximum value around week 34 of pregnancy, after which is gradually reduced until near delivery.
Where Does Amniotic Fluid Come From?
The amniotic liquid derives mainly from the secretion of the membranes surrounding the fetus, fetal urine and lung fluid. As specified above, it contains mostly water, but also nutritive substances, exfoliated fetal cells, etc.
The amniotic fluid constantly renews – it`s swallowed by the fetus and then eliminated during urination. Thus, the recirculation of the amniotic fluid occurs at every 3 hours. So, as a conclusion, the fetus has an important role in maintain the normal level of this liquid.
A small part of this liquid diffuses into the umbilical cord and reaches into the pregnant woman`s circulation.
What Does Amniotic Fluid Smell Like?
Amniotic liquid is clear and has a slight smell. Sometimes, it has a close odor to semen, a bleachy smell. If you pay attention, you cannot mistaken for urine.
What Is the Role of Amniotic Fluid?
- Protects the baby from external shocks.
- Ensures your baby an environment with a constant temperature.
- Maintains the umbilical cord in a normal position (if this is compressed, the amount of oxygen transferred to the baby will decrease and lead to his death).
- Help the baby develop his bones and muscle tone, offering weightlessness and allowing him to move freely.
- Helps the proper development of the lungs.
During delivery, after the rupture of membranes, the amniotic fluid leaks and the lubrication of the vaginal canal is performed to ease the child`s transition and at the same time removes germs from the genital tract. – Read this!
The amount of amniotic liquid is checked by the doctor on ultrasound during prenatal examinations. The amount of liquid is appreciated either subjectively (amniotic liquid in a normal, decreased or increased amount) or objectively (calculating the amniotic fluid index, or FCI, by ultrasound).
Can You Leak Amniotic Fluid?
You expecting a baby, you might feel like everything may leak. For instance, you may have a full bladder, so you might leak a bit of urine. This will make it rather hard to make the difference between the types of leaking you are experiencing: urine, vaginal fluid or amniotic liquid. However, amniotic liquid is clear, tinged with blood or mucus and somehow white-flecked, so this might help you make the difference.
If you aren`t use if it`s urine or amniotic liquid, use a pad and stay lied down for a half an hour. If when standing up you`ll feel a small gush, it may be amniotic liquid. This isn`t normal, because a woman shouldn`t leak amniotic liquid until going into labor.
What Are the Causes of Leaking Amniotic Fluid?
Spontaneous rupture of membranes (SROM) is considered the most common cause. This is a physiological condition that results from an excess pressure and tension occurred in the amniotic cavity. This is normally a sign of labor and it`s more commonly known as water bag leaking.
What Does It Feel Like When Your Water Breaks?
One of the most common concerned of a pregnant woman is water breaking. Before the amniotic sac breaks, most of the times the woman will feel regular contractions, so because of these last warnings she`ll have some time to prepare. Other women will be quite far into labor without even noticing. However, most of the times women will feel a popping sensation or a warm rush when water breaks.
PH Level of Amniotic Fluid & How Much Liquid Is Normal?
This involves testing the amniotic liquid`s pH. The normal limits are between 4.5 and 6.0, while between 7.1 and 7.3 you can interpret a high pH of your amniotic fluid. – Learn about this!
Normally, there are between 500 and 1,000 ml of amniotic liquid in the amniotic cavity. The baby swallows this liquid which reaches his stomach and digestive tract, it`s absorbed in the fetal circulation and then passed through the kidneys, where it`s discharged by urine and, thus recycled.
In some pregnancies, some medical conditions may occur that relate to this fluid:
- Oligohydramnios – too little amniotic liquid.
- Polyhydramnios – excessive amniotic fluid.
Oligohydramnios or Oligoamnios (Not Enough Amniotic Fluid)
Oligohydramnios is characterized by an insufficient amount of amniotic liquid in relation with the stage of pregnancy. Oligohydramnios occurs more frequently during the second part of pregnancy. Another cause is lack of proper function of the placenta. The presence of diagnosis requires a detailed evaluation of the fetus and fetal growth monitoring.
In case that FCI presents a level of liquid of less than 5 cm, the absence of a “pocket” of liquid with a depth of 2 – 3 cm or a volume of liquid smaller than 500 ml at 32 – 36 weeks of pregnancy, then the doctor will most likely put a diagnosis of oligohydramnios.
Around 8% of pregnant women may have low levels of amniotic fluid, cca. 4% of them are diagnosed with oligohydramnios.
This medical condition may occur any time during pregnancy, but it`s more likely to appear in the third trimester of pregnancy. If a woman passed her term with at least 2 weeks, she risks of having low levels of amniotic liquid, because it can decrease to half once she reaches 42 weeks of pregnancy.
Olygohydramnios may cause complications in around 12% of pregnancies that pass over 41 weeks.
Causes of Low Amniotic Fluid
So, if you are losing amniotic fluid, you may ask yourself what`s causing this? Normally, the amount of amniotic liquid is reduced during the last weeks of pregnancy. Still, a series of factors may contribute in reducing the amount of amniotic liquid earlier in pregnancy.
- Congenital malformations: Problems with kidney or urinary tract development, which might cause insufficient urine production, leading in low amniotic liquid levels.
- Placental problems: If the placenta doesn`t produce sufficient blood and nutrients to the child, then he may no longer recycle liquid.
- Leaks or ruptures of membranes: It might be a small stream that flow constantly. This may be due to the rupture of membranes. A premature rupture of membranes may also lead to low levels of amniotic liquid.
- Post term pregnancies: A pregnancy that has exceeded its terms (more than 42 weeks) might include low levels of amniotic fluid, which might be the result of placental function decline.
- Maternal complications: Factors like the mother`s dehydration, high blood pressure, preeclampsia, diabetes mellitus or chronic hypoxia might have an effect on the level of amniotic liquid.
As already mentioned, the amniotic liquid is essential for the baby`s development of lungs, muscles, limbs and digestive system. During the second trimester of pregnancy, the baby starts to breathe and swallow the liquid and the lungs will start to grow and mature.
Also, the amniotic fluid helps in developing the baby`s leg muscles and provides sufficient space for him to move freely.
In case of diagnosis of oligohydramnios during the first half of pregnancy, there might be severe complications, among them:
- Compression of fetal organs, resulting in birth defects.
- Increased risk of miscarriage or stillbirth.
If case the detected during the second half of pregnancy, complications may include:
- Intrauterine growth retard.
- Premature birth.
Complications during labor may include:
- Umbilical cord compression.
- Liquid impregnated with meconium.
- Birth by Caesarean birth.
Treatment for low levels of amniotic liquid is based on the age of pregnancy. If you have been diagnosed with oligohydramnios, the obstetrician will carefully monitor your pregnancy to prevent the occurrence of complications. Tests, like the nonstress test or contraction stress test, may be performed to monitor the baby`s activity. If you are near term, the most doctors will recommend delivering the baby as soon as possible. Other treatments may include:
- Amnioinfusion during labor through an intrauterine catheter. The addition of fluid helps in childbirth and makes it less likely the need for performing a Caesarean operation.
- Infecting fluid through amniocentesis before birth. Oligohydramnios might reappear a week after this procedure, but it may help doctors to visualize fetal anatomy and make a diagnosis.
- If necessary, rehydration of the mother, both orally and intravenously.
Polyhydramnios (Excess of Amniotic Liquid)
Polyhydramnios, also known as hydramnios, represents an accumulation of amniotic liquid in excess. This occurs only for 1% of pregnancies and in 50% – 60% of cases, no one knows why the woman produces more amniotic fluid. – Read about this!
Most cases of polyhydramnios are mild and occur due to the gradual growth of the amniotic liquid amount during the third trimester of pregnancy, and often there are few or no symptoms. Severe polyhydramnios determines difficult breathing, premature birth and other symptoms.
This medical condition can be the consequence of a fetal abnormality of the gastrointestinal tract or central nervous system, a poorly controlled diabetic mother or chromosomal malformations. Other causes are:
- Twin to twin transfusion syndrome (TTTS), a complication possible of a multiple pregnancy with identical twins in which one of the fetuses receives too much blood, and the other too little.
- Fetal anemia.
- Blood incompatibility between the mother and baby.
- Sometimes the cause may be unclear.
- Fetal infection.
- Diabetes – Some mothers with diabetes may experience increased levels of amniotic liquid.
Signs & Symptoms
Pregnant women with polyhydramnios seem to be pregnant in a higher month then they really are, because their abdomen is bigger due to the excessive amount of amniotic liquid. The obstetrician will suspect that you have polyhydramnios is your uterus is increased in size, but the fetal heart rates and the shape of the fetus are difficult to evaluate. Other symptoms are:
- Abdominal discomfort.
- Difficult breathing due to the compression of the increased uterus on the lungs.
- Swollen ankles
- Swollen vulva.
- Swollen inferior abdomen.
The earlier in pregnancy occurs and the high is the amount of amniotic liquid, the more severe are the complications. Polyhydramnios is associated with:
- Premature birth.
- High blood pressure induced by pregnancy.
- Infections of the urinary tract during pregnancy.
- Premature rupture of membranes.
- Excessive fetal development.
- Placenta abruption.
- Umbilical cord prolapsed – when the umbilical cord descends into the vagina before the baby.
- Caesarean birth.
- Severe vaginal bleeding due to lack of uterine muscle tone after birth.
Tests & Diagnosis
If the obstetrician suspects, he`ll recommend an ultrasound. The amount is appreciated either subjectively or objectively (like mentioned above).
If the doctor will detect polyhydramnios by ultrasound, he`ll check in detail the development of the baby to detect the possible causes that may have led to the accumulation of the amniotic fluid. You`ll need to perform some additional tests, such as: amniocentesis, glucose challenge test or karyotype.
The doctor will monitor the pregnancy carefully, maybe with a weekly ultrasound examination to measure the amount of amniotic liquid. In addition, he`ll check the health of the baby by performing a series of investigations:
- Nonstress test.
- Biophysical profile.
- Doppler test.
- Contraction stress test.
The treatment depends on the severity of the condition. An easy form of polyhydramnios will usually disappear by itself and will rarely need treatment, while more severe forms of polyhydramnios will require treatment, such as drainage of excess liquid. The doctor will use amniocentesis in this purpose. Sometimes, the procedure needs to be repeated several times while the pregnancy evolves, which is known as amnioreduction. This intervention has a low risk of premature birth, placenta abruption or premature rupture of membranes. – More info!
Also, the doctor may recommend treatment with indomethacin to reduce fetal urine production and decrease the amniotic liquid amount. Indomethacin isn`t recommended after the week 31 of pregnancy, due to a risk of developing fetal heart problems. – Read here!
In other cases, it`s required the treatment for the base disease, such as gestational diabetes.
In case that you are diagnosed with polyhydramnios, you`ll be carefully monitored and it will be intervened immediately if any complications occur. Inform the medical staff about your condition (don`t even think about giving birth at home) to be prepared for anything that may happen during birth.
Don`t worry! Everything will most likely be fine.