The mother was a first-time mother, and the baby was conceived naturally. The mother enjoyed eating cheese both before and during the pregnancy. She noted decreased fetal movements at 31 weeks and 1 day, and increased abdominal tension and bloating at 31 weeks and 2 days. Ultrasonography revealed intestinal dilatation and peri-intestinal strong echo patterns in the fetus, and the mother was sent to our hospital on suspicion of fetal meconium peritonitis due to intestinal tract perforation. Ultrasonography performed on arrival at the hospital revealed fetal heartbeats and fetal movements, together with dilated gastric bubbles and honeycomb-shaped intestinal dilatations (Figures 1A,B). The amniotic fluid index (sum of four quadrant measurements of the deepest pocket in the vertical dimension with a normal range of 5-25 cm) was high (27 cm). The echo intensity of the gastric bubbles and amniotic fluid was biphasic, with areas of high intensity. The maximum systolic blood flow velocity of the middle cerebral artery was 71 cm/s, which suggested severe anemia. The cardiotocogram revealed the disappearance of baseline fetal heart rate changes. Based on the above findings, we suspected hydramnios and hematogenous amniotic fluid and determined that the nonreassuring fetal status was due to intestinal obstruction and impaired placental function. Therefore, an emergency Cesarean section was performed due to the nonreassuring fetal status. The amniotic fluid was brown and had a mixture of turbidity due to fecal material and old blood. The baby cried immediately after delivery and had no bradycardia. Immediately after birth, old bloody fluid was withdrawn from the oral cavity and stomach, and one minute after birth, watery old bloody stools were seen at the anus. The Apgar scores at 1 min and 5 min were 8 points and 9 points, respectively. The birth weight was 2,127 g, height was 45 cm, and the newborn's vitals were stable. There was no external malformations. Ultrasonography revealed dilatation of the small intestine, and chest radiography revealed little intestinal gas (Figures 2A,B). Peripheral blood examination revealed a low Hb level of 12.7 g/dl. The white blood cell count was 47,100/mul (Seg: 50.0%, Band: 12.0%, Eosino: 6.0%). Leukocytosis and eosinophilia were initially observed; however, the eosinophil count started to decrease thereafter. The patient's clotting profile was normal, PIVKA-II was 69 mAU/ml, and vitamin K deficiency was ruled out. Blood culture was negative; sputum and stool culture did not detect any significant bacteria either. The stool mucus test revealed eosinophil accumulation. The IgE level was 2 IU/ml (not elevated). The specific IgE antibody titers by CAP-Radioallergosorbent test method test was negative for milk antigens (alpha-lactoglobulin, beta-lactoglobulin, milk, and casein, at <0.10 UA/ml each). Allergy testing by the allergen-specific lymphocyte stimulation test (ALST) was negative for kappa-casein (SI 0.79), positive for lactoferrin (SI 3.21), and negative for alpha-lactalbumin (SI 1.48). Bloody stools and intragastric residues decreased and improved with time after admission. Oral food challenge test of the extensively hydrolyzed protein formula (new MA-1, Morinaga Milk Industry Company, Ltd., Tokyo, Japan) was started at 3 days of age. After that, she underwent an oral food challenge test using breast milk without maternal intake of dairy product and was allowed to feed independently on breast milk without dairy products after 48 days of age. Her condition stabilized and she was discharged from the hospital at 67 days of age. She is currently corrected 11 months old, and no neurodevelopmental disorders are observed. This study was approved by the Institutional Review Board of the Ethics Committee of the University of Tokyo Hospital (approval ID: 2701).