Is the duration of human pregnancy decreasing? A vision of Darwinian medicine

Abstract

Why do actual females have a 9-months-pregnancy? Here, we hypothesize that the pregnancies of prehuman species were longer than currently (10 or 11 months), and that anatomical and metabolic changes, by increasing the in-utero size of the fetal brain, selected groups with premature delivery, low-calcified and/or not welded cranial vault bones (permitting deformation during the expulsion), until reaching a current pregnancy duration of 9 months.

Keywords:

• Obstetrical dilemma
• paleontology
• premature birth
• brain size
• encephalization
• parturition
• labor
• gestational age

Ethical approval

This article does not contain any studies with human participants or animals performed by any of the authors. Informed consent statement is not applicable.

Disclosure statement

No potential conflict of interest was reported by the author(s).