Hypoplasia of abdominal wall muscles following massive fetal persistent chylous ascites without anemia

Abdominal wall hypoplasia is a widely known clinical finding of genetic disorders such as the prune belly syndrome. On the other hand, there are few cases of abdominal wall muscle hypoplasia associated with fetal ascites due to fetal hydrops caused by fetal anemia have been reported. We report a case of fetal chylous ascites without anemia, resulting in abdominal wall muscle hypoplasia and flabby skin. At 17 weeks of gestation, fetal ascites was first detected and deteriorated without anemia. At 28, 33 and 36 weeks of gestation, paracentesis was performed three times because of cardiovascular impairment, confirming chylous ascites. After birth, the baby exhibited a flabby skin and lateral abdominal wall hypoplasia, resulting in difficulties in maintaining a sitting posture at 10 months of age. The genetic test using the TruSight One Sequencing Panels found no genetic variants. This case suggests that abdominal wall hypoplasia could be associated with fetal ascites without anemia.