In humans, the energetic cost of pregnancy is about 50,000 dietary calories — far higher than previously believed, a new study found. By Carl Zimmer It takes a lot of energy to grow a baby — just ask ...

As the chair of the department of obstetrics and gynecology at UT Southwestern Medical Center, Catherine Spong is used to seeing a lot of baby bumps. But through her decades of practice, she’s been ...

All species must reproduce to continue their existence. Furthermore, they must raise enough offspring to replace individuals who die. If reproduction falls below replacement level, a population ...