Scientists say they are closer to knowing why older women are more likely to produce abnormal eggs

According to BBC health

The Newcastle University team saw a fall in levels of proteins called cohesins, essential for chromosomes to divide properly for fertilisation.The discovery brings scientists a step closer to explaining why older mothers have less chance of conceiving and a greater risk of giving birth to an abnormal baby, and could point the way to a remedy. The researchers concluded that mistakes during meiosis cell division, which result in abnormal division of chromosomes in older egg cells, are not due to age-related defects in structures in the cell or in the cell’s energy production, which are known to drive ageing in other cells in the body. The researchers suggest that the cause of defects in meiosis can be narrowed down to proteins that regulate the chromosome-separation process.

The research is published, with two other papers, in the journal Current Biology.

It was already known that pregnancy problems in older women can be linked to eggs containing the wrong number of chromosomes, but not why this occurred.

But Professor Balen, who is also chair of the British Fertility Society's practice and policy committee, added it was "far too early to say" if the finding would have any bearing on clinical care for older women with fertility problems.