Miscarriage is one of the most common pregnancy issues in the world. Up to 25% of all pregnancies in the first term end in miscarriage. The number could be higher, as there are many women who don’t even know they are pregnant when they lose the embryo.
There are some known issues which lead to miscarriages in the first term, including immune disorders, blood coagulation disorders and chromosomal abnormalities, but researchers are now adding a new potential cause of miscarriage: the lack of stem cells in the uterine lining.
Researchers from the University of Warwick and University Hospital?s Coventry and Warwickshire NHS Trust found a link between repeated miscarriage and the lack of stem cells in the uterine lining. Researchers were trying to find an underlying illness in women who suffered repeated miscarriages, but when they found none, they started to look for another explanation for the miscarriages.
They started to look into the implantation process and the uterine lining for changes that might lead to miscarriage.
Easy to conceive, hard to keep the pregnancy
One of the first things they found was that women with obesity had a low number of stem cells. Doctors also noticed that women were able to conceive with a lot of ease, but were not able to keep the pregnancies. This made the researchers look into the uterine lining and they noticed a link between methylation changes and miscarriage. This is the process used by the body to control the development of the embryo. The process is called epigenetic and a big epigenetic signature is found in stem cells, according to Dr. Leon Reyfman, stem cells specialist.
The researchers found the epigenetic signature was lacking in women who suffered repeated miscarriages. This means that their bodies were not responding to the chemical signals of the embryo, so they were not able to decide if they should keep it or discard it. Eventually, the body decides not to invest in the pregnancy. As a result, the embryo was discarded.
Premature aging and inflammation
The lack of stem cells in the uterine lining leads to premature aging and inflammation. The inflammation doesn’t prevent conception, but it prevents the embryo development, as the body fails to produce the hormones needed to create the placenta and protect the pregnancy.
There is also good news in this finding. Because the body gets rid of the embryo and the uterine lining at the same time, suffering multiple miscarriages doesn’t mean you won’t be able to support a pregnancy. Most women eventually manage to deliver a healthy baby after a full time pregnancy.
Future research is needed to understand how to maintain a good stem cell population in the uterine lining and how to develop a therapy which can increase the stem cell population to reduce the risk of miscarriage.