Humans have walked the earth for about 200,000 years but still have a lot to learn about human birth, according to an article published in the current New England Journal of Medicine.

Bringing together the most current research on human birth from around the world, the article by Endocrinologist Professor Roger Smith* from the Hunter Medical Research Institute (HMRI) describes how much our species knows about its origins.

"Human birth is unique, which is why we still don’t understand how it works. Because no animals deliver the same way as humans, research into the area has been held back,” said Professor Smith, Director of the HMRI Mothers and Babies Research Centre at John Hunter Hospital.

"Even the chimpanzee, our nearest relative which shares almost 95% of human DNA sequences, reproduces differently, with notable differences in the female pelvis.

"Global research has identified a number of differences that set humans apart from other animals in the way that birth occurs. What makes human birth different is the nature of the hormonal changes that determine the length of pregnancy and the way that labour is initiated."

As the human species has evolved, the way that females give birth has changed. Changes to the female pelvis occurred after humans began to walk upright, and in modern times, the size of the human head has increased and speech, as a form of communication, is critical to human birth. As a result of these changes, women need help to deliver their babies. No other species requires the assistance of another member of the group while giving birth.

"While we have much to learn, scientific progress is being made. As we learn more about this critical part of our lives we can reduce the social costs of premature birth,” said Professor Smith.

"The collective goal of scientists worldwide is to predict which pregnancies carry a risk of pre-term birth and to intervene with appropriate measures. Preventing pre-term birth can make a big difference to a baby’s lifelong health as pre-term birth increases the likelihood of a number of conditions such as cerebral palsy, blindness and intellectual handicap."

HMRI is a partnership between Hunter New England Health, the University of Newcastleand the community.

* Professor Roger Smith is a Professor of Endocrinology at the University of Newcastleand Director of the Endocrinology Unit at John Hunter Hospital.