IVF success and IVF failure
The uterine lining
Some studies have looked at the cells which make up the uterine lining. Proteins on the surface of the uterine lining cells have been identified and some of these seem to be necessary for normal implantation. These surface proteins on the cells of the uterine lining are produced by genes inside the uterine cells.
Chromosomes, genes, DNA and RNA
Like all cells in the body, the cells of the uterine lining are very complex and active. Each cell contains the same chromosomes. Those chromosomes contain genes which are the “blueprints” for producing proteins in the cell.
Genes are composed of DNA. In order to make proteins, the cell “reads” the DNA and produces RNA. The RNA is then used as the template to make proteins. A very important point to understand is that cells in different locations will have different groups of genes that are active. Scientists can tell which genes are active by looking at which types of RNA are present in the cell. Some RNA will “leak” out of cells into the circulation and can be identified and even measured in blood.
Scientists have also attempted to make predictions by comparing the patterns of active genes between individuals.
Recent IVF study
In trying to understand why some IVF cycles work and others don’t, the team from Ireland examined active genes by measuring RNA in the blood, an easily accessible biological sample.
Blood samples from women were taken at eight different stages during the period around conception and the early stages of the IVF cycle. Five of these samples came from women who achieved clinical pregnancies, three from those who had embryos transferred but failed to have any of them implant, and three from women with a history of infertility who managed to conceive on their own without treatment.
Analysis showed that 128 genes were more than twice as active in women with an early pregnancy compared with a non-pregnant state.
The genes were identified as belonging to several different groups. The included genes involved with:
- The growth of new blood vessels
- Blood vessel constriction
- Repair of damage to cell structures
- The supply of energy to cells
By looking at the patterns before these women started fertility medication, they found that over 200 genes were active in women who went on to achieve an IVF pregnancy compared with those who did not.
These findings hold out the promise that doctors using these techniques may someday be able to predict women who may not be able to achieve pregnancy using IVF. With a little luck, it may be even be possible to find treatments that could convert a woman with an unfavorable pattern into a favorable one. Of course, these possibilities are a long, long way off.