Approximately 20% of women develop a hernia at the belly button after pregnancy due to weakness exacerbated by stretching and pressure.

“A large number I would say maybe even as high as 20% of women after pregnancy develop a hernia and the belly button you know the belly button was the site of your umbilical cord when you were in utero and so there was always an opening there and it's scars closed when you're born but it's an inherent spot of weakness so the act of pregnancy where the abdominal wall is stretching and the pressure inside is building up as the uterus grows can pop that open and a lot of women develop hernias”