Meet the scientists!

It’s well known that women find it more and more difficult to get pregnant as they older. Whereas the chance of getting pregnant (assuming a few other important events take place) is generally quite high in the 20s, its much lower in the 40s. A major reason for this is the egg. For reasons that are very poorly understood, eggs which are ovulated by younger women are usually healthy – but eggs ovulated by older women have a high chance of having the wrong number of chromosomes (‘aneuploid’). These eggs are usually unhealthy (not surprisingly – having the wrong number of chromosomes is kind of a big deal). So, although they may get fertilised, they will almost certainly not develop into a healthy baby. In fact, most of these oocytes probably die before the woman even knew she was pregnant.

This is pretty important as these days couples want to wait longer before starting a family.

I try to understand how eggs normally try to make sure they have the right number of chromosomes… and how this might go wrong as women get older. This involves lots of staring down microscopes looking at chromosomes and the part of the egg which is normally responsible for making sure that the egg has the right number – the spindle. See attached image – the egg is the big round thing, the spindle is the bright green oblong part within the egg, and the chromosomes are in blue (the image on the right is a zoom of the left, the egg is eighty um wide – fifteen side-by side make 1mm). Our most important findings so far have been discovering different ways in which egg spindles are different to spindles in other cells – and our hope is that this will eventually lead us to understanding what goes wrong…