An Ottawa scientist has identified a critical reason for the fertility problems suffered by many older women — and has put forward a deceptively simple approach to improving the quality of their egg cells.
Work by Dr. Johné Liu, a senior scientist at the Ottawa Hospital Research Institute, suggests that older women do not produce enough of an important enzyme during ovulation, when the egg cell matures and is released from the ovary.
The enzyme, ornithine decarboxylase (ODC), produces a chemical compound, putrescine, essential for cell division.
But Liu discovered that putrescine also plays a critical role in ensuring that an ovulating woman produces a healthy egg with the correct number of chromosomes.
Women in their late 30s and early 40s often produce eggs with the wrong number of chromosomes.
A recent study of more than 20,000 eggs, collected for in vitro fertilization, revealed that more than 40 per cent of eggs from women over the age of 40 were defective.