Congenital Diaphragmatic Hernia Congenital diaphragmatic hernia (CDH) is a birth defect that occurs when a baby’s diaphragm doesn’t correctly form during fetal development. More Information More Home Doctors Services Home Doctors Services Showing 1 - 1 of 1 Services and Treatments Service General Pediatric Surgery Lehigh Valley Reilly Children’s Hospital is home to the largest pediatric surgery team in the region. We offer state-of-the-art care for routine surgical procedures and are on the leading edge in minimally-invasive (small-scar) pediatric techniques.