Pleural Effusions – What You Need to Know as a Parent
Overview
A pleural effusion is when extra fluid collects around your baby’s lungs inside the chest. During pregnancy, doctors can see this fluid on an ultrasound, where the lungs look like they are floating in water.
The most common cause is called chylothorax, which happens when a small tube in the chest (thoracic duct) doesn’t form right. This fluid usually builds up more on one side and can push the heart to the other side. Too much fluid can keep the lungs from growing well and may cause serious heart problems or fluid buildup in the baby’s body (called hydrops).
Pleural effusions can also happen because of other health issues in the baby, like infections, genetic problems, tumors, or heart issues. Sometimes, the exact cause isn’t known until after birth.
What Happens Next?
The outcome for babies with pleural effusions can be very different. Some fluid collections go away on their own. But if the fluid is large or causes heart failure, treatment before birth may help.
How Is It Treated?
A common treatment is placing a small tube called a thoracoamniotic shunt. This tube drains the extra fluid from around the lungs into the amniotic fluid around the baby. This helps the lungs grow better and reduces pressure on the heart.
After Treatment
Doctors will monitor your baby closely with ultrasounds to check the fluid and lung growth. Treatment improves chances of survival, especially if fluid buildup or heart problems were serious before the shunt was placed.
A pleural effusion is a collection of excess fluid that builds up in the space that surrounds the lungs (pleural space). The pleural effusion can be detected during the pregnancy by ultrasound. On ultrasound, the lungs appear to float within the excess fluid in the pleural space. The causes of pleural effusions can be varied, and is usually split up into primary and secondary causes.
The most common cause of primary pleural effusions is chylothorax. Chylothorax is often due to malformation of the thoracic duct within the chest. The pleural effusions are usually not symmetric, and often displace the heart to one side of the chest. The excess fluid in the chest may cause underdevelopment of the lung tissue and lethal pulmonary hypoplasia, as well as compression of cardiovascular structures and eventual fetal hydrops (heart failure) and death. Pleural effusions can also be caused by an underlying fetal condition, such as a chromosomal abnormality, infection, tumor, cardiovascular abnormality, and/or other syndromes. Despite a thorough evaluation of the fetus for these secondary causes of the pleural effusion, the diagnosis may not be made until after the baby is born.
Fetal pleural effusions from chylothorax have a variable outcome, from complete spontaneous resolution to fetal hydrops and death. Improved perinatal survival has been documented in fetuses with persistent pleural effusions with hydrops or impending hydrops treated by thoracoamniotic shunting. A thoracoamniotic shunt is a tube that is placed into the chest of the fetus so that one end is in the pleural space and the other end is protruding out of the chest and into the amniotic cavity. This tube allows for drainage of the pleural effusion into the amniotic fluid. By decompressing the pleural effusion, the lungs can develop more normally and the heart can function better.