Hydrops Fetalis

What is hydrops fetalis?

Hydrops fetalis is severe swelling (edema) in an unborn baby or a newborn baby. It is a life-threatening problem. There are two types: immune and nonimmune.

What causes hydrops fetalis?

There are two types of hydrops fetalis. The type that a baby has will depend on the cause.

Immune hydrops

This type of hydrops is not very common. It may develop because of Rh disease in the mother. If you are Rh negative and have an Rh positive baby, your immune system attacks your unborn baby’s red blood cells. This causes anemia. Hydrops can occur if the developing baby's organs can't overcome the anemia. The heart starts to fail. Large amounts of fluid build up in the baby's tissues and organs. This type of hydrops is not common today because Rh negative women are often treated with Rh immunoglobulin to prevent this problem.

Nonimmune hydrops

This is the more common type of hydrops. This type includes all other diseases or complications that may interfere with how your baby manages fluid. Some of the diseases or conditions that can cause nonimmune hydrops include:

  • Severe anemia

  • Infections present before birth

  • Heart or lung defects

  • Chromosomal abnormalities and birth defects

  • Liver disease

  • Twin to twin transfusion

What are the symptoms of hydrops fetalis?

Symptoms can be different for each child. Below are the most common symptoms of hydrops.

During pregnancy, symptoms may include:

  • Large amounts of amniotic fluid

  • Thickened placenta

  • Ultrasound of the unborn baby that shows enlarged liver, spleen, or heart. It may show a fluid buildup around the baby’s abdominal organs, heart, or lungs.

After birth, symptoms may include:

  • Pale coloring

  • Severe swelling overall, especially in the baby's belly (abdomen)

  • Trouble breathing

  • Enlarged liver and spleen

Many of these may be caused by other health problems. Hydrops is almost always diagnosed during pregnancy or right at birth.

How is hydrops fetalis diagnosed?

Before birth, your baby may need these tests:

  • Ultrasound. This test uses sound waves to create images of blood vessels, tissues, and organs. The healthcare provider will use the ultrasound to look at how your baby's internal organs are working. The provider can see how blood flows through different vessels.

  • Fetal blood sampling. This is done by placing a needle through your uterus and into one of your baby’s blood vessels or the umbilical cord.

  • Amniocentesis. This test is done by removing some of the amniotic fluid around your baby for testing.

How is hydrops fetalis treated?

Treatment of hydrops depends on the cause. During pregnancy, hydrops may be treatable only in certain cases. You may need to deliver your baby early. In a newborn baby, treatment may include:

  • Help for breathing problems. This may be with extra oxygen or a breathing machine (ventilator)

  • Removing extra fluid from spaces around the lungs, heart, or inside the belly using a needle

  • Fetal blood transfusion may be used with immune hydrops.

What are possible complications of hydrops fetalis?

The severe swelling that occurs with hydrops can overwhelm the baby's organ systems. About 50% of live-born babies with hydrops don’t survive. Risks for other problems are also high for babies born with hydrops. Survival often depends on the cause and treatment.

Key points about hydrops fetalis

  • Hydrops fetalis is severe swelling (edema) in an unborn baby or a newborn baby. It is a life-threatening problem.

  • Hydrops develops when too much fluid leaves the baby's blood and goes into the tissues.

  • It is almost always diagnosed during pregnancy or right at birth.

  • Treatment of hydrops depends on the cause.

  • About 50% of live-born babies with hydrops don’t survive.

Next steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.

  • Before your visit, write down questions you want answered.

  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.

  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.

  • Ask if your child’s condition can be treated in other ways.

  • Know why a test or procedure is recommended and what the results could mean.

  • Know what to expect if your child does not take the medicine or have the test or procedure.

  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your child’s healthcare provider after office hours. This is important if your child becomes ill and you have questions or need advice.

Medical Reviewer: Donna Freeborn PhD CNM FNP
Medical Reviewer: Mary Terrell MD
Medical Reviewer: Stacey Wojcik MBA BSN RN
Date Last Reviewed: 8/1/2023
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