Making eggs in adults

A new study in PLoS Genetics has thrown fuel onto a controversial debate in the field of fertility research - the question of whether mammalian females, including women, can make new eggs cells after birth or not. Many researchers believe that egg cells are only formed when a female foetus develops in the womb, and no more eggs are made after it's born.

But when scientists from Massachusetts General Hospital and the University of Edinburgh reassessed data from a study in mice published in the journal back in February, they came to the surprising conclusion that there was evidence to suggest that egg cells could divide after birth. Although there's a lot more work to be done to prove it - and it's unknown whether this phenomenon also occurs in humans - it raises the intriguing possibility that adult females may be able to make new egg cells as they age.