Locking twins are multiple-birth babies about to be delivered who
are positioned so that their chins are hooked together. This rarely occurs, but
it can happen when the first infant to be delivered is feet-first (breech) and
the next is head-down (vertex).
Locking twins are delivered by cesarean section (C-section).
Sarah Marshall, MD - Family Medicine & William Gilbert, MD - Maternal and Fetal Medicine