Evolution of the human birth canal - American Journal of …
It seems puzzling why humans have evolved such a small and rigid birth canal that entails a relatively complex process of labor compared with the birth canal of our closest relatives, the great apes. This study reviewed insights into the evolution of the human birth canal from recent theoretical and empirical studies and discussed connections ...
Long-held theory on human gestation refuted: Mother’s metabolism, not ...
2012年8月27日 · An anthropologist suggests that the length of human pregnancy is limited primarily by a mother's metabolism, not the size of the birth canal. The research challenges the long-held notion of...
Obstetrical dilemma - Wikipedia
It is said that females with a large head possess a birth canal that can better accommodate large-headed neonates. Mothers with large heads usually give birth to neonates with large heads. Therefore, the detected pattern of covariation contributes to ease childbirth and has likely evolved in response to strong correlational selection. [ 23 ]
Difficult Labor: Birth Canal Issues - Healthline
2016年2月24日 · Remaining in the birth canal for too long can be harmful for a baby. The contractions can compress their head, causing delivery complications. Birth canal issues can result in prolonged...
- [PDF]
Expert Review ajog
humans not give birth at an even earlier developmental stage of the fetus, at a time when the fetus could easily fit through the birth canal? Multiple lines of medical evidence suggest that birth at an earlier develop-mental stage would have many disad-vantages for human neonates. For instance, delivery before term entails considerable health ...
Evolution of the human birth canal - ScienceDirect
2024年3月1日 · It seems puzzling why humans have evolved such a small and rigid birth canal that entails a relatively complex process of labor compared with the birth canal of our closest relatives, the great apes. This study reviewed insights into the evolution of the human birth canal from recent theoretical and empirical studies and discussed connections ...
The evolution of pelvic canal shape and rotational birth in humans
2021年10月11日 · Rotational birth is necessary as the human birth canal is not a uniform structure: its largest dimensions are oriented in different directions in the three “planes” of the pelvis, the inlet, the midplane and the outlet (Fig. 1). In most women, the pelvic inlet has its longest diameter in the mediolateral (ML) direction, but the longest ...
Large heads, narrow pelvises and difficult childbirth in humans ...
2015年4月22日 · Scientists have identified adaptations in the morphology of the human body, which were unknown so far, a new study shows. The size of the neonatal skull is large relative to the dimensions of the...
C-Section Vs Vagina Birth: Risks, Benefits, And How To Choose
2024年12月10日 · When deciding on whether to have a C-section or vaginal birth, your medical history, pregnancy, and personal preference can all influence your decision. Talk to a trusted healthcare provider about the risks and benefits of each option for …
Birth canal | definition of birth canal by Medical dictionary
birth canal The exit route through which the baby is forced by the contraction of the womb. The canal consists of the widely stretched cervix of the uterus, the vagina, and the small and large external lips-the labia.
- 某些结果已被删除