Polyhydramnios (Excessive Amniotic Fluid)

Amniotic fluid surrounds the baby during pregnancy. While the baby grows, the baby swallows amniotic fluid. The baby’s kidneys produce more fluid which the baby urinates into the womb.

Amniotic fluid also:

• Provides cushioning/protection for the growing infant
• Allows the infant to move about in the womb, which helps with bone and muscle growth
• Promotes lung development
• Regulates temperature in the womb

Polyhydramnios, an excess of amniotic fluid, occurs in about 1% of pregnancies. It is the opposite of oligohydramnios, a condition with too little amniotic fluid. Some of the most common causes of polyhydramnios are as follows:

• Maternal diabetes: Diabetes, including gestational diabetes, can lead to amniotic fluid build up.
• Fetal anomalies: Problems with swallowing or digestion can prevent a baby from swallowing enough amniotic fluid.
• A multiple pregnancy (twins, triplets)
• Genetic causes
• Twin to twin transfusion syndrome (TTTS): In some twin pregnancies, blood from one twin goes to the other. This can result in polyhydramnios and medical problems for both twins.
• Incompatible blood types: If the mother has a positive blood type and the baby has a negative blood type, the baby can develop a type of anemia. This can cause polyhydramnios.
• Fetal heart conditions: This could include a congenital defect or another irregularity with the baby’s heart rate.
• Macrosomia: when the baby is large for gestational age

The largest risks of polyhydramnios are preterm birth and emergencies during labor and delivery. If these complications are not managed properly, the baby can develop permanent injury like hypoxic-ischemic encephalopathy or cerebral palsy. 

Medical staff can diagnose polyhydramnios early and avoid serious complications. Prenatal treatments can reduce the amount of amniotic fluid.

Polyhydramnios can cause serious complications in a pregnancy. The swelling of the uterus leads to complications including:

• Maternal breathing difficulties
• Preterm labor
• Premature rupture of membranes (PROM)
• Unusual fetal presentation
• Umbilical cord prolapse
• Postpartum hemorrhage
• Placental abruption

An ultrasound can indicate the amount of amniotic fluid and help diagnose polyhydramnios. If medical professionals suspect polyhydramnios, they may also perform the following tests:

• Amniocentesis: This is a way of sampling amniotic fluid to test for genetic conditions that may contribute to polyhydramnios.
• Doppler ultrasound: This is a type of ultrasound that can take images of the fetus’s circulatory system.
• Glucose challenge test: This test is for women with diabetes.
• Non-stress test: This is a means of checking for abnormalities in the fetal heart rate

Mild cases of polyhydramnios may not require treatment. Doctors should have their patients come in for extra prenatal checkups to monitor the condition and make sure it does not become severe. 

Additional treatments for polyhydramnios include: 

• Amnioreduction: This treatment involves using a long needle to drain excess amniotic fluid from the uterus. There are certain risks associated with this procedure. Doctors must weigh the risks and talk to the patient when deciding whether it is an appropriate intervention.
• Medications to reduce the amount of fetal urine: This medication can put the fetus’s heart health at risk. Doctors must be careful in determining whether this is the right path. They must also carefully monitor the baby for signs of fetal distress.
• Early induction
• Bed rest: This can help delay preterm labor in cases of moderate polyhydramnios