What tests do we use to diagnose pleural effusions and chylothorax?
We use several tests to diagnose pleural effusions and find its causes. A fetal ultrasound helps us learn the type of effusion. A fetal echocardiogram (a fetal heart ultrasound) and amniocentesis for genetic and infectious testing can help us learn what causes the fluid buildup.
Amniocentesis is a procedure in which we pass a long, thin needle into the mom’s uterus and into the amniotic fluid, which surrounds the baby. We take this fluid out and test it for genetic issues and infectious diseases.
We can also see if there is fluid in the baby’s chest by performing thoracentesis, in which we pass a long, thin needle into the mom’s uterus and into the baby’s chest. We can take fluid from the chest and look at the type of cells in the fluid, which will help us diagnose congenital chylothorax and fetal hydrops.
What can I expect from pleural effusions and chylothorax tests?
Amniocentesis and thoracentesis procedures do not cause the mother much discomfort. They may feel pressure, a cramp or a slight pinch as the needle passes through the uterus. Infectious and genetic testing results typically take 7 to 10 days.
To diagnose for congenital chylothorax, we perform a thoracentesis procedure and test the fluid sample. When the lymph cells (called lymphocytes) are high, it means the fluid is coming from the “leaky” thoracic duct in the baby’s chest. This information gives our fetal care specialists the cause for the fluid buildup and allows for further counseling. The thoracentesis procedure and analysis of the chest fluid typically take less than 2 hours.
These tests carry a very small risk for miscarriage or pregnancy loss and the risk for this is about 1 loss for every 800 procedures performed. In general, the risk of the fetal condition of pleural effusions and chylothorax are a much greater risk and understanding the cause with testing is important in treatment decisions.