An evolutionary argument for why women today need assistance in giving birth may be that

the large brains of Homo sapiens infants necessitate a different pattern of childbirth events than seen in earlier hominids and primates.

True the larger brain of homosapiens infant necessitate a different pattern of childbirth events that seen in earlier hominids and primate.

Explanation: earlier hominids and primate had smaller brain compare to their body size.

But our new generation now have bigger head compared to their body size which is hard or difficult for child birth and need assistance in child birth.