The relatively narrow human birth canal presumably evolved as a 'compromise' between its abilities for parturition, support of the inner organs, and upright walking. But not only the size of the birth ...

During human birth, the fetus typically navigates a tight, convoluted birth canal by flexing and rotating its head at various stages. This complex process comes with a high risk of birth complications ...

Human childbirth is comparatively difficult because our babies' heads are large relative to our birth canals. This tight 'fetopelvic' fit increases the risk of obstructed labor, which in turn has ...