The endometrial polarity paradox

Lead researcher

Dr Jemma Evans

Main finding

The lining of the uterus, the endometrium, undergoes changes to allow implantation of an embryo. In the current study we found the polarity of endometrium is altered. Think of polarity in terms of a magnet; the 'equal poles' of a magnet will repel each other. The same principle is thought to happen within the endometrium at the time of embryo implantation. If the epithelial cells within the endometrium are polarized they may repel the embryo. We found that molecules which control the polarity of the epithelial cells, to which the embryo must attach, are reduced around the optimal time for embryo implantation


Centre for Reproductive Health

Research group

Endometrial Remodelling


Ms Sarah Whitby, Prof Lois Salamonsen

Journal and article title

Most surprising

We anticipated that the polarity molecules may be reduced in the epithelial cells. However, we were surprised to observe that the same molecules were increased in another cell type within the endometrium, the stromal cells. These stromal cells within the endometrium are unique, as the menstrual cycle progresses they undergo and transformation process known as decidualization. This decidualization process is critical for pregnancy. As the stromal cells became decidualized they demonstrated an increase in these polarity molecules and this increase was controlled by the hormones estrogen and progesterone. Conversely in epithelial cells the same hormones decreased polarity molecules leading to the polarity paradox within this unique tissue; the same hormonal environment both increased and decreased polarity within different cell types.

Future implications

The polarity molecules within the endometrium may be manipulated to enhance reproductive success and combat recurrent pregnancy loss.

Disease/health impact

Female infertility

Dr Jemma Evans at Hudson Institute