This sometimes happens when the fetal head is larger than the mother's pelvic girdle (cephalopelvic disproportion).

Cephalopelvic disproportion, a combination of a large fetal head and a mother's narrower pelvic structure.

This is called cephalopelvic disproportion.

Factors that predispose to face presentation are prematurity, macrosomia, anencephaly and other malformations, cephalopelvic disproportion, and polyhydramnios.

In obstetrics a trial of labour is the conduction of spontaneous labour in a moderate degree of cephalopelvic disproportion.

Failure to progress in labor and cephalopelvic disproportion (meaning the baby's head is too big to fit through the pelvic cavity): These factors account for about 30 percent of c-sections.

One way is for doctors to check all possibilities before diagnosing cephalopelvic disproportion (CPD)-which means the baby's head is too big to fit through the mother's pelvis and that a cesarean is a must.