aftercoming

A following state, sequel, consequence, or result; an aftercome.

Succeeding, following.

They establish (saith he) by the reason of their judgement, that whatsoever is reported of hell, or of after-comming paines, is but a fiction[…].

I set them down here, that their names may be a stink and ill-savour to aftercoming generations, as apostate from the way of God[…].

Specifically, of a baby's head: following the rest of the body out of the womb, rather than (as is usual) preceding it.

The most important aspect of an assisted vaginal breech delivery is careful delivery of the aftercoming head.