An Adelaide research centre has made a world-first fertility breakthrough, which may give older women fresh pregnancy hopes by repairing eggs that have deteriorated over time. 

The breakthrough will be welcome news to the increasing number of women choosing to start families later in life.

Dr Hannah Brown and her team from the University of Adelaide’s Robinson Research Institute found haemoglobin was present in good eggs but missing from bad quality eggs.

According to the research, the haemoglobin inside the eggs makes them more efficient and appears to alters the way the egg uses energy and the amount required.

In trials on mice, haemoglobin was added to bad eggs and then fertilized. From these eggs grew healthier embryos.

Australian law does not permit trials on humans, but trials have begun in Belgium, where women are allowed to donate eggs for scientific purposes.

Researchers in Belgium are conducting experiments where haemoglobin is added to eggs that have been collected from women.

Scientists are hopeful that the process could be available in humans within five years.