Which among the following is TRUE regarding umbilical cord?
High-Yield Explanation
The cord at term normally has two aeries and one vein. The right umbilical vein usually disappears early during fetal development, leaving only the original left vein. At bih, the mature cord is approximately 50-60 cm in length and 12 mm in diameter. A long cord is defined as more than 100 cm, and a sho cord as less than 30 cm. Umbilical coiling index (UCI) is defined as the number of complete coils divided by the length of the cord in centimeters. Clinically, hypocoiling (UCI 0.3 coils/cm) is related to fetal-growth restriction and intrapaum fetal acidosis and asphyxia. Both have been linked to trisomies and single umbilical aery Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 3. Implantation, Embryogenesis, and Placental Development. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.