Hernias in babies and children usually develop when there is a weakness in the belly muscles, which allows the intestines or other organs to push through the openings. Inguinal and umbilical hernias happen for slightly different reasons. During pregnancy, all babies have an area called the inguinal canal. This goes from the abdomen to the genitals. In boys, this canal lets the testicles move from the belly to the scrotum, the sac that holds the testicles. Normally, a baby’s inguinal canal closes shortly before or after birth. But in some cases, the canal doesn’t fully close, and then a loop of intestine can move into the inguinal canal through the weak spot in the belly wall, causing an inguinal hernia. Most inguinal hernias happen in boys. As for umbilical hernias, they occur when there is a small opening in the abdominal muscles that is left after birth. A loop of intestine can then move into the opening between the belly muscles, causing an umbilical hernia. Hernias happen more often in children who have one or more of the following risk factors: being born early or premature, having a parent or sibling who had a hernia as an infant, cystic fibrosis, developmental dysplasia of the hip, undescended testes, or abnormalities of the genitourinary system.