Non-Immune Hydrops

What is Non-Immune Hydrops?

Fetal hydrops, or hydrops fetalis, is a serious condition in which fluid builds up in two or more areas of the baby’s body, causing severe swelling. The condition can be fatal.

The fluid may accumulate:

• in the abdominal cavity (ascites)
• around the lungs (pleural effusion)
• around the heart (pericardial effusion)
• in the skin or scalp (edema)

Types of Hydrops (Pleural effusion)

There are two types of fetal hydrops:

• Non-immune hydrops, the most common type, is caused by a fetal medical condition or birth defect that affects the body’s ability to manage fluid. Up to 90% of all cases of hydrops today are non-immune hydrops.
• Immune hydrops occurs when the mother’s immune system attacks and destroys the baby’s red blood cells due to incompatible maternal and fetal blood types. This form of hydrops is uncommon today because of medication available to prevent the condition.

How does hydrops (pleural effusion) affect my baby?

Hydrops poses serious risks to the fetus and pregnancy including:

• Severe swelling
• Enlarged spleen, heart or liver
• Thickened placenta
• Polyhydramnios (excess amniotic fluid)
• Preterm birth
• Heart failure
• Stillbirth
• For babies that survive, breathing problems at birth due to underdeveloped lungs

In some cases, maternal mirror syndrome may occur, where the mother’s condition mirrors the fetus, causing pre-eclampsia and swelling that endanger her health and require immediate delivery.

Prognosis

The prognosis for each baby depends on the underlying cause of the hydrops, gestational age and whether treatment is possible.

An estimated 50% of babies with hydrops don’t survive until birth.

In general, the earlier in the pregnancy the condition occurs, the greater the risk to the fetus. 

Causes and Prevalence

The reported incidence rate of non-immune hydrops varies widely, with estimates ranging from 1 in every 1,000 to 4,000 births.

Causes of non-immune hydrops include:

• Severe fetal anemia
• Congenital infections
• Heart or lung defects
• Chromosomal abnormalities and genetic abnormalities
• Twin-twin transfusion syndrome
• Fetal bleeding (hemorrhage)

In many cases, the exact cause is not identified. 

Diagnosis

Hydrops is typically diagnosed during a routine ultrasound that finds abnormal fluid accumulation in at least two areas of the baby’s body. 

If hydrops is diagnosed you may be referred to a fetal center for a comprehensive evaluation and specialized care.

At Texas Children’s Fetal Center, we arrange for you to visit as quickly as possible for a detailed assessment by a team of specialists experienced in the diagnosis and treatment of this life-threatening condition, including maternal-fetal medicine (MFM) physicians, fetal imaging experts, hematologists, genetic counselors and neonatologists.

Additional testing to determine the severity of the condition and underlying cause may include:

• High-resolution anatomy ultrasound
• Ultra-fast MRI for a more detailed view of fetal anatomy and function to identify birth defects
• Fetal echocardiogram to evaluate the fetal heart
• Amniocentesis and chromosomal analysis to screen for genetic abnormalities
• Fetal blood sampling, a procedure similar to an amniocentesis to obtain a fetal blood sample from the umbilical cord (also known as percutaneous umbilical cord blood sampling, or PUBS)
• Maternal blood type and screening, to determine if the cause is Rh alloimmunization, for antibody testing, and to determine TORCH titers to check for various infections that can cause hydrops

Following this thorough evaluation, our specialists will meet with you about your results, answer any questions you have, and discuss your baby’s prognosis and possible treatment options.

In some cases, hydrops is not diagnosed until after birth. Symptoms in a newborn may include difficulty breathing, anemia, pale skin, severe swelling throughout the body, and enlarged liver and spleen.

Treatment During Pregnancy

You and your baby will be closely monitored with regular ultrasounds to watch for signs of complications and determine if early delivery is needed. Non-stress testing may also be used to monitor the baby’s well-being.

Treatment during pregnancy will depend on the underlying cause of hydrops and gestational age.

Fetal treatment strategies include:

• Intrauterine blood transfusion in cases of fetal anemia
• Placement of a shunt (drainage tube) in the fetal chest, in cases of pleural effusion, to continually drain excess fluid accumulating around the lungs
• Intrauterine administration of medications for fetal arrhythmia
• Corticosteroids to improve fetal lung development and reduce the risk of breathing difficulties in preterm births

Delivery

For the best possible outcome, delivery should take place at a hospital with the specialized care and resources required by babies with hydrops, including the highest level neonatal intensive care unit (NICU) for premature or critically ill newborns.

Delivery should be carefully planned and coordinated with a team of specialists experienced in managing these high-risk pregnancies and deliveries. Our Fetal Center team works closely with pediatric experts from Texas Children’s Hospital, including neonatologists experienced in the treatment of newborns with hydrops, ensuring the best possible care for your baby every step of the way.

Texas Children’s is consistently ranked one of the best children’s hospitals in the nation by U.S. News & World Report.

Treatment after Birth

Treatment needs after birth depend on the underlying cause of hydrops and the health of the newborn.

Treatment strategies include:

• Breathing support
• Removal of excess fluid from spaces around the lungs, heart, or abdomen
• Blood transfusion
• Surgery to repair a defect, such as a heart or lung malformation
• Medications to treat the underlying cause

Postnatal Care Team

A unique and distinct advantage for mothers delivering at Texas Children’s Pavilion for Women is our location inside one of the largest and most renowned children’s hospitals in the world, for seamless access to the critical care services and specialists your child may need after birth.

For newborns with fetal hydrops, this means no transfers during critical postnatal periods. It also means that the pediatric specialists responsible for treating your child have been an integral part of their care team since before birth.

Depending on your baby’s needs, his or her postnatal care team may include:

• Neonatologist
• Hematologist
• Pediatric Surgeon
• Pediatric Genetics