Dayton Children’s Hospital

Pleural Effusion

What is pleural effusion?

Pleural effusion, or hydrothorax, is a buildup of fluid in the layer of tissue that surrounds your baby’s lungs (the pleural space). The excess fluid can make it difficult for your baby to breathe. In some cases, pleural effusion only affects one lung; in other cases, it affects both lungs.

There are several potential causes of fetal pleural effusion. For example, certain medical conditions, such as chylothorax or hydrops fetalis, can lead to pleural effusion. Other potential causes include chromosome abnormalities, heart failure, infection or other lung problems.

How is pleural effusion diagnosed?

Pleural effusion is diagnosed during pregnancy during a routine ultrasound. The ultrasound can easily see an abnormal fluid collection in your baby’s chest. In other cases, it is not diagnosed until after the baby is born and begins to show symptoms. Common symptoms include:

  • Shortness of breath
  • Rapid breathing
  • Difficulty feeding
  • Fever
  • Cough

While examining your baby, the doctor will first listen to your baby’s lungs with a stethoscope. If the doctor thinks your baby may have fluid in the lungs or if your baby is showing symptoms of pleural effusion, tests may be done to confirm the diagnosis. Common tests include:

  • Chest X-ray
  • Computerized tomography (CT scan)
  • Ultrasound

How is pleural effusion treated?

The treatment goals for pleural effusion are to drain the fluid, keep it from building up again and to determine the cause so that it can also be treated. If the pleural effusion develops prior to the baby being born, the fluid may compress the developing lungs and prevent normal development. If this happens prior to 30 weeks’ gestation, it can be potentially life threatening.

If discovered during pregnancy, the pleural effusion may be treated while the baby is still in the womb. This can be by either draining the fluid by inserting a small needle under ultrasound guidance into the baby’s chest (thoracentesis), or by inserting a shunt (a specialized catheter) into the baby’s chest. The shunt continuously drains the fluid from the baby’s lungs into the amniotic fluid. Draining the fluid while the baby is still in the womb gives the baby’s lungs a better chance of developing normally, and may be lifesaving.

If pleural effusion is not diagnosed until after your baby is born, there are several possible treatment methods. The most common is called a thoracentesis, a procedure in which a needle is inserted into the pleural space and the fluid is drawn out into a syringe. This helps your baby to breathe better and allows doctors to examine the fluid to try to determine what is causing the buildup. If it is due to chylothorax, it may be necessary to prolong the drainage of the chyle. Special formula, IV parenteral nutrition and medications may be used to decrease the chylous fluid collection.

Doctors also commonly treat pleural effusion by inserting a tube through a small incision in the baby’s chest to drain the excess fluid. This procedure is called a tube thoracotomy. 

How will pleural effusion affect my baby during and after surgery?

Whether or not your baby will need surgery will depend on the amount of fluid buildup, whether or not the fluid buildup is recurring and the cause of the pleural effusion. Many instances of pleural effusion are mild, in which case they can sometimes be cured by thoracentesis or by a tube thoracotomy. In other cases, more extensive surgical treatments may be required to fix the underlying cause or to repair damage to the lungs.