A woman’s bone marrow can determine her ability to conceive and bear a fetus, Yale researchers at PLOS Biology said.
The study shows that after the fertilization of the egg, the stem cells leave the bone marrow and pass through the bloodstream to the uterus, where they help transform the uterine mucosa for implantation. If the mucous membrane does not undergo this significant transformation, the embryo cannot be implanted, and the pregnancy is terminated, Medicalxpress reported.
We always knew that two things are necessary for pregnancy: the ovaries and the uterus. However, the realization that bone marrow plays an important role is a paradigm shift, said the author of the study, Professor Hugh Taylor.
Previous studies have shown that stem cells derived from bone marrow contribute to the non-immune environment of the non-pregnant uterus, but it remains unknown whether stem cells affect the pregnant uterus and how. In this study, it was possible to prove the physiological significance of stem cells for pregnancy.
Some of these bone marrow-derived mesenchymal stem cells move into the uterus and become decidual cells necessary for the process of implantation and pregnancy maintenance, Dr. Reshef Tal, co-author of the study, explains.
In two models of mice with a Hoxa11 gene defect, which is presented in mice as an endometrial defect, researchers found that bone marrow transplantation from a healthy donor can improve fertility by promoting sufficient decidualization of the endometrium. In mice with only one copy of the defective gene, the graft saved the pregnancy, which would otherwise have been interrupted, and increased litter sizes, whereas in mice with two poor copies of the gene, the graft caused growth and restoration of the defective endometrium.
An antimetabolite drug has been used that is still considered chemotherapy, but it does not harm the ovary, and therefore mice can still become pregnant, which allows us to track the transplanted bone marrow cells and examine their role in reproduction Tal said.