Intrauterine intussusception presenting as fetal ascites at prenatal ultrasonography

Intrauterine intussusception, an uncommon cause of bowel obstruction, has rarely been detected by prenatal ultrasonography. We report two cases of intrauterine intussusception after gestation, which presented as isolated fetal ascites at 30 weeks of gestation by ultrasonography. In case 1, on the follow-up ultrasonography at 32 weeks of gestation, the previously observed ascites had disappeared, whereas the echogenicity of the bowel was increased without any sign of dilation, suggesting the presence of meconium peritonitis. The fetus was delivered at 39 weeks. In case 2, however, the amount of fetal ascites became increased, and the fetus was delivered at 34 weeks of gestation. After delivery, both infants were surgically explored with resection of the ileum with end-to-end anastomosis because of intrauterine intussusception and ileal atresia. From the experience of these cases, we suggest that the ultrasonographic finding of isolated or transient fetal ascites might contribute to the early diagnosis and management of intrauterine intussusception.