Hydrops Fetalis

What is hydrops fetalis?

Hydrops fetalis is a severe, life-threatening problem of severe edema (swelling) in the fetus and newborn. It is also called hydrops. There are two types of hydrops:

• Immune. This results when the mother's immune system causes a breakdown of red blood cells in the fetus. This is the most dangerous complication of blood group incompatibility between the mother and baby. This type of hydrops is uncommon, however, because of the widespread use of Rh immunoglobulin treatment for Rh negative women. 

• Nonimmune. This is the more common type. It can result when diseases or complications interfere with the baby's ability to manage fluid.

What causes hydrops fetalis?

Hydrops develops when too much fluid leaves the bloodstream and goes into the tissues. Many different diseases and complications can cause hydrops, including the following:

• Immune hydrops may develop because of Rh disease in the mother. When an Rh negative mother has an Rh positive baby, the mother's immune system sees the baby's Rh positive red blood cells as "foreign." When the mother's antibodies attack the foreign red blood cells, they are broken down and destroyed, resulting in anemia. Hydrops can develop as the baby's organs are unable to compensate for the anemia. The heart begins to fail and large amounts of fluid build up in the baby's tissues and organs.

• Nonimmune hydrops includes all other diseases or complications that may interfere with the baby's ability to manage fluid. There is no one mechanism to explain nonimmune hydrops. Some of the diseases or complications that are often associated with hydrops include the following:

  • Severe anemias

  • Congenital infections (infections present at birth)

  • Heart or lung defects

  • Chromosomal abnormalities and birth defects

  • Liver disease

Why is hydrops fetalis a concern?

The severe edema that occurs with hydrops can overwhelm the baby's organ systems. About half of unborn babies with hydrops do not survive. Risks for other complications are also high for babies born with hydrops, with survival often depending on the cause and treatment.

What are the symptoms of hydrops fetalis?

The following are the most common symptoms of hydrops fetalis. However, each baby may experience symptoms differently.

During pregnancy, symptoms may include:

• Large amounts of amniotic fluid

• Thickened placenta

• Ultrasound of the fetus shows enlarged liver, spleen, or heart, and fluid buildup surrounding the fetus' abdomen, heart, and lungs

After birth, symptoms may include:

• Pale coloring

• Severe edema overall, especially in the baby's abdomen

• Enlarged liver and spleen

• Respiratory distress (difficulty breathing)

The symptoms of hydrops fetalis may resemble other conditions or medical problems. Always consult your baby's doctor for a diagnosis.

How is hydrops fetalis diagnosed?

In addition to a complete medical history and physical examination, diagnostic procedures for hydrops fetalis may include:

• Ultrasound. A diagnostic imaging technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. Ultrasounds are used to view internal organs as they function, and to assess blood flow through various vessels.

• Fetal blood sampling. This is done by placing a needle through the mother's uterus and into a blood vessel of the fetus or the umbilical cord.

• Amniocentesis. Involves withdrawing some of the amniotic fluid for testing.

Treatment for hydrops fetalis

Specific treatment for hydrops fetalis will be determined by your baby's doctor based on:

• Your baby's gestational age, overall health, and medical history

• Extent of the disease

• Your baby's tolerance for specific medications, procedures, or therapies

• Expectations for the course of the disease

• Your opinion or preference

Treatment of hydrops depends on the cause. During pregnancy, hydrops may be treatable only in certain situations. Early delivery may be recommended. Management of hydrops in newborn babies may include:

• Help for respiratory distress using supplemental oxygen or a mechanical breathing machine

• Removal of excessive fluid from spaces around the lungs and abdomen using a needle