Which factor can complicate a delivery of an infant in breech presentation?

In a breech presentation, the infant is positioned in the uterus with the buttocks or feet facing downward, which can lead to complications during delivery. The size of the infant can significantly complicate a breech delivery because a larger infant may not fit through the birth canal as easily. This can increase the risk for various issues, such as obstructed labor, a higher chance of injury to both the mother and infant, or the need for an emergency cesarean section if the delivery does not proceed properly.

In breech deliveries, the other factors, while they may influence labor dynamics in general, do not directly cause as significant complications specific to the mechanics of a breech birth. The position of the placenta, for instance, can create its own set of challenges (like placenta previa), but in the context of breech deliveries, the infant's size and the accompanying difficulties it introduces are more direct and critical factors to consider.