Nuchal cord type A and type B

Nuchal cord type A and type B need to be distinguished at delivery. Type A encircles the neck in an unlocked pattern. Type B encircles the neck in a locked pattern. In a prospective review of nuchal cords the type B pattern occurred in 1 in 50 births. Cesarean section and stillbirth were associated with type B nuchal cord.(Am J Obstet Gynecol 1997;177:94.)