London: In a first, scientists have found that a lack of stem cells in the womb lining causes women to suffer from recurrent miscarriages, a breakthrough that could lead to new treatments for the condition.
"We have discovered that the lining of the womb in the recurrent miscarriage patients we studied is already defective before pregnancy," said Jan Brosens, Professor at the University of Warwick in the UK.
"I can envisage that we will be able to correct these defects before the patient tries to achieve another pregnancy. In fact, this may be the only way to really prevent miscarriages in these cases," said Brosens.
The team found a shortfall of stem cells is the likely cause of accelerated ageing of the lining of the womb which results in the failure of some pregnancies. Miscarriage is the most common cause of loss; between 15-25 per cent of pregnancies end in miscarriage and one in 100 women trying to conceive suffer recurrent miscarriages, defined as the loss of three or more consecutive pregnancies.
The researchers examined tissue samples from the womb lining, donated by 183 women. The team found that an epigenetic signature - which is typical of stem cells - was absent in cultures established from womb biopsies taken from women suffering recurrent miscarriages.
Indeed, fewer stem cells could be isolated from the lining of the womb from recurrent miscarriage patients when compared to women in the study's control group. The researchers further found that a stem cell shortage accelerates cellular ageing in the womb.
The lining has to renew itself each cycle, each miscarriage and successful
birth. This renewal capacity is dependent on resident stem cell population. A shortage of these stem cells in patients suffering recurrent loss is associated with accelerated ageing of the tissue.
Ageing cells mount an inflammatory response, which may facilitate implantation of an embryo but is detrimental for its further development. "After an embryo has implanted, the lining of the uterus develops into a specialised structure called the decidua, and this process can be replicated when cells from the uterus are cultured in the lab," said Brosens.
"Cultured cells from women who had had three or more consecutive miscarriages showed that ageing cells in the lining of the womb don't have the ability to prepare
adequately for pregnancy," Brosens added.
The researchers behind the breakthrough will soon start studies into a treatment which they believe could bring hope to those who have suffered failed pregnancies. The study was published in the journal Stem Cells.
