Polyhydramnios

What is Polyhydramnios?

Polyhydramnios is a condition where there is too much amniotic fluid during pregnancy. This condition can be risky for both the mother and the baby. It can lead to a higher chance of the baby dying in the womb, early labor, the waters breaking prematurely, the umbilical cord slipping out of the womb, the baby being unusually large, the baby lying feet first in the womb, cesarean birth, and the mother bleeding excessively after delivery. In pregnancies with polyhydramnios, about 20% can be traced back to a birth defect. However, in 60% to 70% of cases, there is no clear cause for the condition.

Polyhydramnios happens when the balance between the production and absorption of amniotic fluid is disrupted. The symptoms and severity of this condition depend on the amount of amniotic fluid and the root cause. Diagnosing polyhydramnios usually involves an ultrasound. If the fluid pocket is more than eight centimeters or the total amount of fluid exceeds 25 centimeters, it suggests polyhydramnios.

If severe polyhydramnios is suspected, further checks and monitoring of the baby in the womb are needed to find out the cause, plan care, and decide when the delivery should take place. Treatments like an amniocentesis (removing fluid from around the baby) or medicine (indomethacin) are only used for severe cases. It’s recommended that the delivery takes place in a specialist care center.

What Causes Polyhydramnios?

Polyhydramnios is a condition where there is too much amniotic fluid in the womb during pregnancy. The most common reason for this to happen is unknown, but doctors usually only decide this once they have looked at and eliminated other possible causes.

One of the key reasons that can cause polyhydramnios is if the baby isn’t able to swallow properly, since swallowing helps to reduce the amount of amniotic fluid. Other factors related to the baby that can cause this condition include infections the baby can get while still in the womb, such as TORCH infections, abnormalities in the chromosomes, problems with the urinary system, and disorders that affect the muscles and nerves.

In the case of twins sharing a womb, a rare but serious situation called twin-twin transfusion syndrome can happen, where one twin gets too much amniotic fluid.

There are also a few conditions related to the mother that can lead to polyhydramnios. These include gestational diabetes, which is a type of diabetes that only happens when a woman is pregnant, and a condition called alloimmunization, where the mother’s antibodies lead to a type of anemia in the baby.

Risk Factors and Frequency for Polyhydramnios

Polyhydramnios, a condition where there’s too much amniotic fluid around the baby in the womb, occurs in 1% to 2% of all pregnancies. It’s often found by accident during ultrasound checks in the third trimester. While it usually resolves on its own, in rare cases, an underlying cause may be found after the baby is born.

People with polyhydramnios that has no known cause (idiopathic) are less likely to have an underlying disease or birth defect. However, about 91% of those with more severe polyhydramnios do have an underlying condition. These individuals are more likely to show symptoms due to the large amount of amniotic fluid.

A study by Chamberlin used ultrasound to measure amniotic fluid volume in over 7,500 high-risk pregnancies. The study found that the perinatal mortality rate (the number of babies who die around the time of birth) for those with normal amounts of fluid was about 2 deaths per 1,000 pregnancies. But for those with polyhydramnios, this doubled to roughly 4 deaths per 1,000 pregnancies.

Signs and Symptoms of Polyhydramnios

Polyhydramnios is a condition typically discovered by chance, as it often shows no symptoms or is unrecognized in standard examinations. Polyhydramnios occurs when there’s an excess amount of amniotic fluid, which is the fluid that surrounds the baby in the womb. For pregnant women experiencing symptoms or who are diagnosed with polyhydramnios through ultrasound, the focus is usually on detecting risk factors. These can include glucose intolerance, sexually transmitted diseases, infections and conditions that may cause a decrease in neuromuscular function, such as certain neurological conditions and anemia.

Sometimes, women diagnosed with polyhydramnios experience difficulty breathing because the excess amniotic fluid puts pressure on the diaphragm. This can make it harder for the diaphragm to move as it should.

• Tightness in the abdomen
• Swelling in the lower extremities

Abnormalities such as an unusually large womb, or the womb growing too quickly, suggest the possibility of an overly large baby or polyhydramnios. Special scans are often required to confirm the diagnosis and to monitor other potential issues related to pregnancy. Polyhydramnios may lead to premature labor or premature rupture of the membranes (PROM), which is when the water breaks before labor starts. It might also cause the baby to be in an unusual position or put the umbilical cord at risk. Some cases could require a cesarean section delivery, especially if the baby is too large. There is also a risk of heavy bleeding after birth due to the uterus being overstretched by the excess volume of amniotic fluid.

Testing for Polyhydramnios

Ultrasound is commonly used by doctors to check the health of a baby and the amount of amniotic fluid in the womb. Amniotic fluid is the liquid that surrounds and protects the baby in the womb. The volume of this fluid can be assessed using the Single Deepest Vertical Pocket (SDVP) method or the Amniotic Fluid Index (AFI).

The SDVP method involves measuring the deepest area of amniotic fluid in the womb that doesn’t contain any parts of the baby or the umbilical cord. If the measure is less than two centimeters, it can indicate a low level of amniotic fluid, known as oligohydramnios. Normal measures are between two to eight centimeters. When the measure is above eight centimeters, it indicates polyhydramnios, which means there’s too much amniotic fluid. This can be mild (8-11 cm), moderate (12-15 cm) or severe (more than 16 cm).

The AFI method involves adding up the amount of amniotic fluid in four different areas of the womb. Normal measurements range from 5 to 25 cm. If the measure is less than 5 cm, this indicates oligohydramnios. If it’s more than 25 cm, this indicates polyhydramnios. Doctors sometimes use color Doppler imaging (a type of ultrasound) to help see the baby’s umbilical cord while measuring.

If a doctor diagnoses polyhydramnios, they will try to figure out the underlying cause. It can be due to a number of factors such as abnormalities in the baby, genetic diseases, maternal (mother’s) diabetes, having more than one baby (twins or triplets), infections in the baby, and more.

All pregnant women undergo a routine ultrasound scan between weeks 18 to 22 to check for any abnormalities in the baby and if there is more than one baby. If polyhydramnios is severe, the doctor will use ultrasound to check for any structural abnormalities in the baby like deformities in the oral, esophageal, tracheal or intestinal areas, heart defects, and other things. It’s also important for doctors to assess if the baby is too big or too small as there is a link between larger babies and polyhydramnios.

Doctors monitor the growth of the baby and the level of amniotic fluid repeatedly, particularly in the third trimester, since polyhydramnios can lead to risks for the baby. If needed, they can perform amniocentesis, a procedure to remove excess amniotic fluid, in some severe cases.

Doctors may perform blood tests to help identify the cause of severe polyhydramnios. All pregnant women usually get a diabetes test at around 28 weeks to rule out the possibility that high sugar levels in the mother’s blood could be causing polyhydramnios. Doctors also screen for various infectious diseases that could be a potential cause.

For some cases of polyhydramnios, doctors might perform genetic tests to check for genetic abnormalities in the baby. For example, Noonan syndrome, a genetic disorder that can cause a wide variety of symptoms and physical abnormalities, can sometimes be associated with polyhydramnios and can be diagnosed by gene sequencing.

Treatment Options for Polyhydramnios

If you have polyhydramnios, a condition where there’s too much amniotic fluid around the baby during pregnancy, the treatment will depend on how severe the condition is and what’s causing it. Mild and unexplained polyhydramnios usually don’t require any treatment.

However, if the condition is severe or leads to symptoms, you might have to see a specialist in maternal-fetal medicine. This specialist can help monitor the baby’s growth and determine the best timing and method for delivery through ultrasound scans. It’s usually best to deliver at a specialized hospital because severe polyhydramnios can create risks for both the mother and the baby.

In some cases, the specialist might recommend a procedure called reductive amniocentesis. This procedure removes some of the excess amniotic fluid to reduce symptoms like difficulty breathing due to pressure on the diaphragm or significant discomfort. This procedure doesn’t have many severe side effects but can sometimes lead to early labor, separation of the placenta from the womb, or breaking of water too early. Also, polyhydramnios often reoccurs even after this procedure, so its effectiveness can be limited.

Another possible treatment is a drug called Indomethacin. This drug can lower the volume of amniotic fluid and can also help delay premature labor in severe cases of polyhydramnios. But this drug should be used with caution as it can cause complications in the newborn such as premature closure of a vital blood vessel, low amniotic fluid, white matter damage in the brain, and necrotizing enterocolitis, which is a severe bowel condition in infants. Therefore, the general recommendation is to only use this drug in severe cases where the mother is at risk of preterm labor.

The exact timing of delivery will be based on the severity of polyhydramnios, any present birth defects, and signs of early labor or premature breaking of water. If a mother with polyhydramnios starts labor, doctors may recommend using ultrasound to check the baby’s position and monitor the baby’s heart rate.

Some complications can arise during childbirth due to polyhydramnios. For instance, the uterus can become overstretched causing labor to progress slowly. There’s also a slightly higher risk of the baby’s umbilical cord slipping into the cervix, which could require a cesarean section. Additionally, the newborn might need extra support after birth since there’s a higher chance of rapid breathing (known as transient tachypnea) which can sometimes lead to being admitted to the neonatal intensive care unit (NICU). Mothers can also have a higher risk of heavy bleeding following birth due to the uterus being overstretched.

Lastly, it’s important to note that bed rest doesn’t necessarily prevent complications due to polyhydramnios and can increase the risk of blood clots during pregnancy.

What else can Polyhydramnios be?

Polyhydramnios, or having too much amniotic fluid around your baby during pregnancy, could be caused by a variety of health issues. Some possibilities include conditions that cause quick growth of the abdomen, like:

• Liver disease, fluid buildup in the body (cirrhosis, ascites)
• Heart failure
• Severe kidney disease
• Preeclampsia
• A tumor in the placenta called chorioangioma
• Blood clots in the placenta
• Being pregnant with multiple babies

These conditions can also make the uterus expand quickly, which may lead to difficulty in breathing. This is a common pregnancy symptom that could be caused by a blood clot (like a pulmonary embolism), existing lung conditions getting worse, heart rhythm problems, pregnancy-related heart muscle disease, muscle or skeleton issues, or an infection.

Swelling of the hands and feet is a normal part of pregnancy, but it could also be related to preeclampsia or high blood pressure caused by pregnancy, vein problems, or a deep vein clot.

What to expect with Polyhydramnios

The outlook for mild idiopathic polyhydramnios, a condition where there is too much amniotic fluid around the baby in the womb, is generally very good. The health of the mother and baby may worsen as the condition becomes more severe. Most mild polyhydramnios cases will improve on their own and don’t need any treatment.

Complications can arise if the uterus, the womb that holds the baby, stretches too much because of the excess fluid. These complications may include breathlessness in the mother, early labor, premature breaking of the water bag, the baby not being in the head-down position for birth, the umbilical cord slipping out before delivery, heavy bleeding after childbirth, a large baby tied to maternal diabetes, high blood pressure conditions, and urinary tract infections.

Information on the risk of the baby dying before birth in cases of polyhydramnios is inconsistent. Severe and rapidly worsening polyhydramnios independently increases the risk of death around the time of birth. In addition, babies who are smaller than usual for their stage of pregnancy and also have polyhydramnios have the worst outlook. The prognosis is directly related to the underlying cause of the excess amniotic fluid.

Possible Complications When Diagnosed with Polyhydramnios

Polyhydramnios, a condition characterized by an excess of amniotic fluid in pregnancy, is linked with conditions that may increase the likelihood of negative outcomes for both mother and baby. All these potential risks are connected to the higher volume of amniotic fluid that consequences in expansion of the uterus, which can cause heavy bleeding after childbirth.

Common Risks Associated with Polyhydramnios:

• Increased chances of the baby dying in the womb
• Potential for early labor
• Early rupture of the water bag
• Possibility of the umbilical cord slipping out before the baby during labor
• A larger than average baby size
• Higher possibility of the baby being in a feet-first position in the womb
• Greater chance of needing a cesarean birth
• Potential for heavy bleeding after childbirth

Also, polyhydramnios increases the likelihood of a cesarean delivery due to factors like the umbilical cord slipping out prematurely, the baby being in a feet-first position, and difficulties during labor. There are other complications that may be directly related to the conditions causing the excess of amniotic fluid. For instance, having a baby that’s bigger than average, which happens often in diabetes during pregnancy, can increase the risk for the baby’s blood sugar levels to drop after birth, the baby’s shoulders getting lodged during birth, and a mismatch between the size of the baby’s head or body and the mother’s pelvis, which may require a cesarean birth.

Preventing Polyhydramnios

If you’re pregnant and diagnosed with polyhydramnios, you might be wondering what this means. Simply put, polyhydramnios is a condition where there’s more amniotic fluid than normal in your womb during pregnancy. This can lead to certain health risks for both you and your baby.

To help you understand more, your doctor will give you information about polyhydramnios. This will explain that if the volume of amniotic fluid is above the usual range for your stage of pregnancy, we’ll need to take a closer look at your baby’s stomach, kidneys, and bladder. This is to make sure there are no serious issues.

One potential cause of polyhydramnios is Gestational Diabetes Mellitus (GDM), which is a type of diabetes that develops during pregnancy. So, we may request some lab tests to check if you have GDM.

Remember, your involvement and understanding are very important in managing polyhydramnios during your pregnancy. We encourage you and your family to be active participants in any decisions about your care.