Human Gestation Overview

Study Notes

Gestation Overview

Gestation, the process of carrying developing offspring, has existed for 178 million years.
It involves a crucial maternal-fetal connection for nourishment and protection.
The placenta facilitates this connection, with human placentas being highly invasive, allowing direct fetal-maternal blood contact.
Maternal immune suppression is crucial for preventing the mother's immune system from rejecting the fetus. This is aided by both maternal and fetal factors.
Immune suppression makes pregnant women more vulnerable to severe illnesses like COVID-19.

Implantation and Birth

Gestation starts with embryo implantation in the uterus.
Birth marks the end of gestation and the beginning of lactation.
Post-birth maternal support (lactation) requires more energy expenditure than pre-birth support.
The length of gestation is determined by the time needed to prepare the newborn for independent life.

Human Gestation vs. Other Hominins

Human gestation is longer than other hominin pregnancies, but only slightly.
The extended gestation period in humans results in greater infant fat stores and body weight at birth.
Human infants average 6.1% of their mother's weight at birth; whereas chimpanzee and gorilla infants are proportionally smaller, at 3.3% and 2.7% respectively.
7.5-month premature human infants have a similar weight to 7.5-month chimpanzee infants. More than 80% of 7.5-month human infants survive.
The final 6 weeks of human pregnancy dramatically increase infant size through substantial energy transfer from mother to fetus.

Description

Explore the fascinating process of human gestation, which has evolved over millions of years. This quiz covers key aspects, from embryo implantation to maternal immune responses and the comparison with other hominins. Understand how gestation prepares offspring for life outside the womb.