Prenatal diagnosis of abnormal umbilical cord insertion: a rare case of furcate insertion.

Furcate insertion (FI) is an extremely rare abnormality of umbilical cord insertion. One of the complications associated with FI is hemorrhage from the umbilical vein at the site of FI of the umbilical cord, which can cause sudden intrauterine fetal death. Because of its rarity, no prenatal diagnosis of FI has been reported. A 31-year-old woman at 34 weeks' gestation was referred to us for suspected abnormal cord insertion. Ultrasonography showed normal fetal growth and amniotic fluid volume, with no fetal anomalies. Although the umbilical cord contained three vessels inserted at the center of the placenta, the umbilical vessels separated from the cord substance before their insertion to the placenta. Based on these findings, the patient was diagnosed with FI. During labor at 37 weeks' gestation, fetal heart rate was normal and a healthy neonate was delivered. At macroscopic examination, the umbilical cord was inserted in the middle of the placenta, and the placental parenchymal tissue just under the cord insertion was deficient and had been changed to white, elastic hard tissue. Pathological examination of the white tissue revealed fibrin deposition and focal infarction. Although FI is a very rare condition, prenatal diagnosis can be achieved through detailed color Doppler ultrasound studies. Therefore, taking precautions and keeping in mind the poor fetal outcome associated with FI are preferred.