In Europe, an increasing number of women have bariatric surgery; therefore, obstetricians are likely to encounter these patients. We report a 22-year-old woman, who had previously undergone uncomplicated laparoscopic Roux-en-Y gastric bypass. She was admitted with severe abdominal pain at 35 weeks of gestation. A cesarean section with delivery of a healthy baby in combination with an exploratory laparotomy was performed. Internal herniation was suspected, but not identified during surgery. Three days later she died of a severely gangrenous small bowel secondary to internal herniation. This fatal case illustrates a potential complication and difficulties in the management of pregnant women who have undergone Roux-en-Y gastric bypass. In these women, observation and investigations based on a multidisciplinary approach are vital if abdominal pain develops, with involvement of intestinal surgeons experienced in bariatric surgery, as well as radiologists with specific knowledge of relevant imaging procedures.