Hydrops Fetalis

Hydrops fetalis is a rare, life-threatening condition that occurs when a fetus or newborn has severe swelling (edema). They also have excessive amounts of fluid buildup in at least two body areas. Hydrops fetalis isn’t a disease. It’s a symptom of an underlying health condition affecting the fetus. Another name for hydrops fetalis is fetal hydrops.

Fetal hydrops can lead to:

• Stillbirth
• Preterm labor and delivery
• Illness of the mother
• Severe illness or death of your newborn

The treatment and outlook (prognosis) for the condition vary widely depending on the health issue causing the problem. Sometimes, healthcare providers can treat the underlying health issue. Other times, providers can’t treat the underlying condition, and the outlook is poor.

Types of hydrops fetalis

Healthcare providers divide hydrops fetalis into two different types: immune and nonimmune. The cause of the fluid buildup determines the type.

• Immune hydrops fetalis: Immune hydrops fetalis occurs when your red blood cells are incompatible with the fetus’s red blood cells. This can destroy the fetus’s red blood cells, leading to problems like total body swelling. The resulting severe anemia leads to heart failure.
• Nonimmune hydrops fetalis (NIHF): Nonimmune hydrops fetalis is more common, accounting for up to 9 out of every 10 cases. This type occurs when an underlying medical condition or disease affects the fetus’s ability to manage fluid.

Symptoms of hydrops fetalis

Your healthcare provider may be able to see signs or symptoms of hydrops fetalis on an ultrasound during your pregnancy. These symptoms may include:

• Excessive amount of amniotic fluid
• Thickened placenta
• A large, fluid-filled sac around the fetus’s neck
• Buildup of fluid around the heart
• Buildup of fluid around the lungs
• Buildup of fluid in the abdomen
• Buildup of fluid in the skin and soft tissues
• Enlarged heart, liver or spleen

In addition, you may have:

• Preeclampsia
• High levels of protein in your pee
• Total body swelling

After your baby is born, their symptoms may include:

• Change in skin color
• Difficulty breathing
• Bruising or pinpoint hemorrhages (low platelet count, or thrombocytopenia)
• Heart failure
• Anemia
• Jaundice
• Total body swelling

Hydrops fetalis causes

The cause of hydrops fetalis depends on the reason for the fluid buildup (immune hydrops fetalis or nonimmune hydrops fetalis).

Immune hydrops fetalis

Immune hydrops fetalis usually occurs due to a blood type incompatibility between you and the fetus. If you have different Rh factors (you have Rh negative and the fetus is Rh positive), you’ll make antibodies against the fetus’s red blood cells. This leads to total body swelling. You can prevent this type of hydrops fetalis by getting a RhoGAM shot. This is a medicine that stops your immune system from making the antibodies.

Rh incompatibility is the most well-known cause. But other less common causes of immune hydrops include an immune system reaction to other red blood cell antigens, like the Kell, Duffy and Kidd antigens.

Nonimmune hydrops fetalis

Nonimmune hydrops fetalis occurs when the fetus has an underlying disease, a birth defect or a genetic disorder that affects its ability to manage fluid. These include certain:

• Heart conditions
• Chromosomal disorders
• Metabolic diseases
• Tumors
• Urinary issues
• Blood-related issues
• Red blood cell disorders
• Diseases and infections in the mother

Complications of this condition

Hydrops fetalis can lead to spontaneous miscarriage, preterm delivery and early death of your newborn. In babies that survive, other complications may occur, including:

• Developmental delays
• Chronic lung damage
• Liver damage

When is hydrops fetalis detected?

Healthcare providers usually diagnose hydrops fetalis during pregnancy when they can see signs of the condition on a prenatal ultrasound. Your provider may see:

• Abnormal amounts of fluid around the fetus’s heart, lungs, belly, skin and soft tissues (excessive fluid buildup in two or more body compartments defines nonimmune hydrops)
• An enlarged placenta
• High amounts of amniotic fluid

If your provider detects hydrops fetalis, they may refer you to a high-risk obstetrician or maternal-fetal medicine specialist. They’ll work to quickly determine the underlying cause of the condition. Finding out the cause of fetal hydrops is important because some conditions are treatable. You’ll have more tests, including:

• Amniocentesis
• Fetal blood sampling
• Fetal echocardiogram
• Genetic testing
• Fetal MRI
• Blood tests, including mean corpuscular volume (MCV) and testing for viral infections

Despite these tests, healthcare providers can’t figure out a clear cause of hydrops fetalis in about half of all cases. You’ll work with your providers to determine other possible tests and treatment options. They can tell you more about what to expect during and after pregnancy.

How is hydrops fetalis treated?

Treatment for hydrops fetalis depends on various factors, including:

• The cause of the condition
• The severity of the condition
• The age of the developing fetus

Treatment isn’t always possible during pregnancy, but when it is, it may include:

• Fetal blood transfusion: The fetus receives an injection of red blood cells through the umbilical cord to treat anemia.
• Antiarrhythmic drugs: When the fetus has an irregular heartbeat, you may receive drugs that pass through the placenta to treat it.
• Shunt placement: If the fetus has fluid around the lungs, a surgeon may place a shunt to drain excess fluid.
• Fetal surgery: If the fetus has a teratoma, a surgeon may be able to remove it or use surgery to treat other prenatal problems.

Treatment for a newborn with hydrops fetalis may include:

• Cesarean delivery: If necessary, your provider will deliver your baby through a C-section. Your baby will receive immediate specialized care in the neonatal intensive care unit (NICU).
• Ventilator: Your baby may need extra oxygen or a machine to do their breathing for them (ventilator) if they have difficulty breathing at birth.
• Fluid removal: Your baby’s healthcare provider will remove extra fluid from around their lungs and belly.
• Blood transfusion: Your baby may need a red blood cell transfusion if they have immune hydrops fetalis.

How do I manage hydrops fetalis?

If your healthcare provider detects hydrops fetalis, they’ll closely monitor your pregnancy. You’ll have frequent ultrasounds and other tests to track your health and the health of the fetus. You may have a team of healthcare specialists who are all working to ensure the best possible outcome for you and your baby. This team may include:

• Maternal-fetal specialist
• Pediatric cardiologist
• Neonatologist
• Geneticist
• Nurse specialist care coordinator

One thing your providers will look out for is a condition called maternal mirror syndrome. This is a type of preeclampsia in which you “mirror” the fetus. You develop severe fluid buildup and swelling and may experience other symptoms. If you develop this condition, you’ll have to deliver your baby early for the health and safety of both of you.

What is the outlook (prognosis) for hydrops fetalis?

The outlook (prognosis) for fetuses and babies born with hydrops fetalis varies widely based on several factors, including:

• The underlying cause of the condition
• The age of the developing fetus at diagnosis
• The amount of swelling in the fetus
• Prenatal treatments
• The age of the fetus at delivery
• The extent of treatment necessary at delivery

The overall survival rate is less than 50%. The development of severe hydrops before the third trimester of pregnancy carries a high mortality. Prognosis is better for treatable causes of hydrops — like fetal arrhythmia — and poorer for causes like severe birth defects.

Can hydrops fetalis be prevented?

You can prevent immune hydrops fetalis by getting a RhoGAM shot during and after your pregnancy. This medication prevents your body from producing antibodies against your baby’s red blood cells. You’ll only receive this injection if you’re at risk for Rh incompatibility.

You can’t prevent nonimmune hydrops fetalis.