Polyhydramnios – Causes, Symptoms & Treatment

Amniotic fluid is the clear or tinted yellow fluid surrounding a foetus throughout the pregnancy and keeping it safe inside the amniotic sac. It performs various life-giving functions in the womb, such as allowing free movement of the foetus, aiding lung development, maintaining a constant thermal environment, and protecting against outside impacts and infections. With progress in the pregnancy, the amniotic fluid volume also increases to accommodate the growing foetus. However, the challenge arises when there is too much build-up of amniotic fluid in the uterus during pregnancy, which is termed polyhydramnios in pregnancy. According to the Mayo Clinic, the likelihood of polyhydramnios is about 1% to 2% of pregnancies. While mild polyhydramnios cases may not be very troublesome, severe cases, on the other hand, may require treatment (1). Thus, staying aware of the symptoms and getting a timely diagnosis is crucial.

What Is Polyhydramnios?

The baby in your womb is constantly swallowing the amniotic fluid and excreting it again as urine, thereby maintaining a constant volume of the fluid. Occasionally, this balance can be upset, leading to an abnormal increase in the amount of amniotic fluid. The amount of amniotic fluid is normally between 600 – 800 mL in the later stages of pregnancy. If the amount of amniotic fluid in your uterus exceeds 1.5 litres, you will develop a condition known as polyhydramnios.

In simple terms, by the polyhydramnios definition, we mean the excess build-up of amniotic fluid during pregnancy, which may jeopardise the health of the baby as well as the mother (2).

Is It Common to Have Polyhydramnios?

The volume of amniotic fluid in the uterus increases gradually throughout your pregnancy, until around the 36th week, after which it decreases until delivery. Most cases are mild to moderate, but occasionally, it can be very severe. Polyhydramnios is a rare condition, experienced by less than 1% of all pregnant women.

Polyhydramnios Symptoms

Polyhydramnios usually occurs in the second half of pregnancy, but it can be experienced as early as 16 weeks of pregnancy. Early, mild cases of polyhydramnios usually have no noticeable symptoms. The first symptom is the pressure placed on the belly and internal organs by the amniotic sac. Other common signs of polyhydramnios include (3):

• Shortness of breath
• Constipation
• Heartburn
• Rapid weight gain
• Abdominal and foot swelling
• Reduction in urine
• Fatigue
• Unexpected enlargement of the pregnancy bump (macrosomia)
• Swelling in your vulva (external genitals)

However, these symptoms are very common in pregnant women. If you are concerned about having polyhydramnios or if any of these symptoms become worse, you should see your doctor immediately.

Causes of Polyhydramnios

What causes too much amniotic fluid? Finding a specific cause for polyhydramnios is not easy. In nearly 50% of all cases, a cause cannot be identified. The increase in amniotic fluid could be linked to your health, the baby, or the placenta. The American Pregnancy Association lists some conditions that could lead to moderate to severe polyhydramnios (4):

1. Pregnancy With Twins or Multiple Babies

If you’re carrying more than one baby in your belly, the chances of polyhydramnios is high, especially if you are pregnant with identical twins, who can develop a twin-to-twin transfusion syndrome, in which one foetus receives more amniotic fluid than the other. This creates an imbalance in the flow of fluid in the amniotic sac.

2. Chorioangioma

This is a condition in which there is an abnormal growth on the placenta. Polyhydramnios is one of several other complications.

3. Genetic Defects

The risk of getting polyhydramnios is linked to genetic conditions like Down’s syndrome. Babies with these defects tend to have high amniotic fluid levels surrounding them.

4. Foetal Anaemia

This is a condition in which the baby’s urine output is greatly increased, which in turn increases the volume of amniotic fluid.

5. Swallowing Problems in the Foetus

Sometimes, there might be a blockage in your baby’s food pipe or intestines. Occasionally, this could happen due to neural tube defects, cleft palate, or hydrocephalus. Due to this, the foetus cannot control the level of amniotic fluid as usual.

6. Maternal Diabetes

If you have diabetes or contract gestational diabetes during your pregnancy, your unregulated blood sugar could cause your baby to produce more urine. This increases the fluid in the amniotic sac.

7. Certain Infections

Contracting illnesses like Erythema infectiosum or toxoplasmosis could result in higher amniotic fluid being produced.

Risks of Polyhydramnios

One of the commonly known risk factors for polyhydramnios includes specific health conditions that develop during the gestation period, like gestational diabetes. Gestational diabetes can affect the foetus’ central nervous system, digestive tract, or other organs. It can also put pregnant women at risk of polyhydramnios (1).

Polyhydramnios Complications

The complications depend mainly on the amount of excess amniotic fluid in the uterus. Luckily, polyhydramnios is unlikely to cause many issues with your pregnancy. However, there are a few polyhydramnios risks that you have to look out for (5):

1. Difficulty Giving Birth

It might be tricky for the foetus to enter the pelvis during labour, drawing the umbilical cord out before the baby. This is known as a cord prolapse, and you might have to undergo a caesarean surgery.

2. Placental Abruption

This is when the placenta tears away from the uterine wall during labour, which could lead to haemorrhages.

3. Rupture of the Amniotic Sac

The amniotic sac can rip, making your water break before the due date. This could result in a premature birth.

4. Foetal Malpresentation

If the baby’s feet are facing the cervix in this condition, instead of the usual head-down position, you might need a C-section for successful delivery.

5. Bleeding After Delivery

You might undergo severe bleeding after giving birth due to injuries to your placenta and uterus.

6. Stillbirth

Polyhydramnios increases the risk of a stillbirth, which is the death of the foetus in the uterus.

Diagnosis

If you or your doctor suspects the possibility of polyhydramnios, there are several means by which a successful diagnosis can be made (6).

1. Foetal Ultrasonography

An ultrasound is the most effective technique for checking for polyhydramnios. If there is any evidence, a more comprehensive ultrasound technique can be employed, which can measure the amniotic fluid in four of the deepest uterine cavities. The doctor will then calculate your amniotic fluid index, which is usually between 12 and 24 cm in the 34th week of pregnancy. A value above 25 cm means you have polyhydramnios, with increasing values indicating higher severities.

2. Glucose Challenge

This test checks if you have developed diabetes during pregnancy. If your blood sugar is higher than normal after periodic measurements, gestational diabetes is diagnosed. The presence of this can further confirm polyhydramnios.

3. Karyotyping

This is employed to test for genetic abnormalities in the foetus. The doctor will obtain the foetal cells by taking some of the amniotic fluid or a piece of the placenta. Congenital defects are a strong marker for polyhydramnios.

4. Amniocentesis

This is one of the easiest methods of testing, where amniotic fluid is extracted from the uterus via an injection. The fluid can then be tested for infections and other problems.

Test to Monitor Diagnosed Polyhydramnios

Receiving a diagnosis of polyhydramnios is not as scary as it sounds. Your doctor will have your pregnancy closely monitored, with regular ultrasounds to calculate your amniotic fluid index. Besides amniotic fluid tests, other tests that can be done to estimate the baby’s health are:

1. Specialised Ultrasonography

This technique employs the Doppler Effect to obtain a detailed understanding about the structure of blood vessels and the circulation of blood in the foetus. The ultrasound can also check for foetal defects.

2. Non-Stress Test

A non-stress test is crucial to measure the physical condition of your growing foetus. It is done by calculating the reaction of the foetus’ heart rate during movement. The doctor will place a device on your belly to check the baby’s heart. He might also ask you to consume something to make the baby move around.

3. Biophysical Test

Your doctor may conduct the ultrasonography with the non-stress test in conjunction to gain details about the foetus’ heart and breathing rate, physical structure, and the amniotic fluid test index.

Treatment for Polyhydramnios

As most cases of polyhydramnios are moderate, the condition often resolves itself over time. Your doctor might recommend a few treatments if your case is suspected to be severe.

1. Hospital Admission

You might have to spend a few weeks in the hospital in cases where bed rest is important.

2. Diabetes Treatment

If you have maternal diabetes, meeting with a diabetes specialist is crucial. They will help you reduce the amount of blood sugar in your body, and thereby the level of amniotic fluid. In case of gestational diabetes, treatment for polyhydramnios may be required (7).

3. Induced Labour

If the biophysical tests indicate any foetal abnormalities or defects, you might have to go through early labour at the hospital at about 39 weeks. Once the baby is born, any necessary surgeries can be conducted to help your baby.

4. Medication

There are several medications that can control the amount of amniotic fluid in your uterus, such as indomethacin, usually prescribed in the last trimester. However, the medication might have side effects like stomach irritation, nausea, and vomiting.

How to Manage Polyhydramnios

Polyhydramnios makes you feel bloated and exhausted. Talk to your doctor for suggestions for polyhydramnios management. There are a few things to do at home for relief:

1. Avoid physical activity.

Shortness of breath can be controlled by avoiding too much walking, running, or climbing stairs. Bed rest is strongly recommended to prevent further pain or swelling in your legs. You might even want to postpone the date you start your maternity leave.

2. Control heartburn.

As the uterus exerts pressure on the digestive organs, you might want to control this by eating small, regular meals, staying up after eating for a few hours, avoiding spices in food, sleeping in a slightly upright position, and taking antacid medications.

3. Reduce anxiety.

The stress from your pregnancy and polyhydramnios will have you feeling more anxious than usual. Try to relax more often by meeting friends, going out, watching movies, reading, or taking classes with experienced antenatal professionals.

Is It Possible to Drain Extra Fluid?

Polyhydramnios is mostly harmless, but in extreme cases, it can cause severe complications such as premature births, stillbirths, and uterine haemorrhaging, for which your doctor might suggest amnio-reduction. This process involves manually draining the excess amniotic fluid. This is mostly recommended in cases where labour is premature. The technique used is amniocentesis, where the amniotic fluid is removed via an injection coupled with a vacuum pump to suction out the excess fluid. Usually, around 1 litre is removed during the process.

FAQs

1. Will the baby be healthy with polyhydramnios?

Most pregnant women do not experience any complications from increased amniotic fluid and have a healthy baby. However, in severe cases, complications may arise.

2. Is a C-section necessary in case of polyhydramnios during pregnancy?

A c-section may be prescribed if your doctor feels that a vaginal delivery is extremely risky for the child or the mother.

3. What is the ideal level of amniotic fluid in the uterus during pregnancy?

According to the March of Dimes, the amniotic fluid level increases until about 36 weeks of pregnancy. By that time, the amount of amniotic fluid during pregnancy is about 1 quart. After it starts decreasing slowly (8).

Polyhydramnios pregnancies almost always go through early labour, so early hospitalisation is your best bet. However, if you want to remain at home, ensure you prepare for an emergency delivery at least a few weeks in advance. Make sure you have your close family and partner fully aware of the situation, in case you need help. If you are at home when your water breaks, the most important thing to do is get on your hands and knees to avoid the umbilical cord from prolapsing. If this happens, call an ambulance and wait for them to arrive. Under no circumstances must you try pushing the cord back inside. Try not to eat and drink anything, either. Once you reach the hospital, you will be in safe hands, as the doctor will take care of you from then on.

References/Resources:

1. Mayo Clinic – Polyhydramnios

2. MedlinePlus – Polyhydramnios

3. Cleveland Clinic – Polyhydramnios

4. American Pregnancy Association – Polyhydramnios: High Amniotic Fluid During Pregnancy

5. March of Dimes – Polyhydramnios

6. MSD Manual – Polyhydramnios

7. NHS – Polyhydramnios (too much amniotic fluid)

8. March of Dimes – Amniotic fluid

Also Read:

Ectopic Pregnancy
Leaking Amniotic Fluid during Pregnancy
How to Increase and Decrease Amniotic Fluid During Pregnancy