Perforation of Meckel's diverticulum in a neonate delivered to a mother with hyperthyroidism

Meckel's diverticulum has been known to occur in 2% of the general population and is usually asymptomatic; it causes complications in 4% of cases. We have recently experienced a rare case of perforation of Meckel's diverticulum in a neonate delivered to a mother who had been treated with methimazole for hyperthyroidism during pregnancy. A 2-day-old neonate who was delivered by Cesarean section at 39 weeks' gestation underwent an emergency operation; he was diagnosed with gastrointestinal perforation, showing a large amount of air within the gastrointestinal tract, and pneumoperitoneum radio graphically. Laparotomy showed a perforated Meckel's diverticulum in the jejunum with a moderate amount of serous ascitic fluid. Segmental resection of the small bowel and intraperitoneal drainage were performed. A pathological examination for Meckel's diverticulum revealed a partially thinned muscular layer suggesting the existence of an increase in pressure within the diverticulum. The neonate needed to be administrated thyroid hormone for a hypothyroid state, which was possibly due to the maternal treatment with methimazole during pregnancy. We hypothesize that maternal treatment with methimazole during pregnancy may be associated with the formation of Meckel's diverticulum in a neonate; and it may be associated with an abdominal distention and subsequent perforation of Meckel's diverticulum with secondary hypothyroidism.