Diagnosing
The great majority of babies with CDH have so-called isolated defects. This means that the baby has no other anomalies. CDH can also be a symptom of a genetic defect – this occurs in about 20% of all babies with CDH. Accordingly, once your unborn baby is diagnosed with CDH, it is advisable to carry out genetic tests to confirm or rule out a genetic disorder.
This can only be done by testing the amniotic fluid surrounding the unborn baby (the procedure to obtain a sample of amniotic fluid for this test is called amniocentesis). Amniocentesis is a safe procedure (the risk of complications is less than 1%) which takes only a few minutes and causes very little discomfort. A karyotype test is usually offered to determine if an unborn baby has a genetic disorder associated with CDH. You may also be offered a microarray CGH (also known as array CGH) test which is increasingly used and allows a more accurate genetic assessment.
Fig. 5. Amniocentesis