Many couples who cannot get pregnant spontaneously become parents through in vitro fertilization, IVF (using donor sperm or eggs). The heartbreak of infertility includes knowing for infertile women forced to resort to using donor eggs they will never pass on their genes to their child. However, according to the new study from researchers at the Fundacion Instituto Valencianode Infertilidad (FIVI) and Stanford University suggests infertile women who carry a child fertilized using a donor egg still impart an important genetic gift to their child.
The endometrial fluid (EF), a viscous fluid secreted by the endometrial glands into the uterine cavity of the womb, nurtures the embryo and constitutes the microenvironment in which the first communication between the endometrium of the womb and the embryo. The EF in the womb of the mother contains genetic material. Molecules known as MicroRNAs (miRNAs) that are secreted in the mother’s womb can change the genetic information of the child. A miRNA is a small non-coding RNA molecule that regulate the protein expression, located within the cell and in extracellular environment, including various biological fluids.
Practically speaking, this means the mother’s DNA influences the way the child develops. Her genetic material essentially helps to “decide” which of her child’s genes get turned on and off. Scientists have confirmed so-called Barker’s Theory of 1990, suggests that ‘the womb may be more important than the home,’ emphasizing the concept that the maternal endometrium has a reprogramming effect on the embryo, fetus, and adult. Vilella along with Dr. Carlos Simón, FIVI’s scientific director, and their colleagues proposed miRNAs floating in a mother’s EF might change the embryo. There, EF, which carries a variety of molecules from the mother (including miRNAs) serves as milk to a developing embryo. The delivery of endometrial miRNAs from the maternal endometrium to the pre-implantation embryo involve a cell-to-cell communication mechanism (Hsa-miR-30d) which is taken up by the embryo from the EF. It means, the embryo might modify its DNA and increase its adhesion to the maternal endometrium. Speaking about the findings Doctor Felipe Vilella says, “These findings show us that there is an exchange between the endometrium and the embryo, which is something that we already suspected as a result of the coincidence of certain physical characteristics between mothers and children born through ovodonation and also due to the incidence of diseases in children related to maternal pathologies during pregnancy, such as obesity and smoking.
No matter how she becomes pregnant, a woman performs an invaluable service by carrying the child. This new research suggests she also exerts a significant influence on her child’s genetics, development, and lifelong health.
Source: Vilella F, Moreno-Moya JM, Balaguer N, et al. Hsa-miR-30d, Secreted by the human Endometrium, Is Taken up by the Pre-Implantation Embryo and Might Modify Its Transcriptome. Development. 2015.