By Indira Ivf, IVF Speciality
Uterine Myomas are common. There are many women who suffer from these growths at some point in their lives. However, these are non-malignant growths not associated with any kind of cancer. Nevertheless, these myomas or fibroids may have an impact on fertility in general and embryo implantation in particular.
Studies on the impact of uterine myomas on IVF have come up with the following findings:
Alteration of Uterine Contractions
Uterine contractions have a normal rhythm during the whole ovulation cycle. During the early follicular phase, it’s frequency increases from the distant part to the cervix
and during the luteal phase, it increases from the cervix to the distant part (fundus). Fibroids are known to change the normal pattern of contractility and induce some
kind of inflammatory response. Both of these may have an impact on embryo implantation. Since successful implantation of the embryo is one of the hallmarks of
successful IVF, presence of myoma can affect IVF outcome to some extent.
Reduction of Cytokine Factors
Intrauterine implantation of the embryo is also facilitated by certain cytokines in early pregnancy. These cytokines are responsible for implantation of the embryo and its
development, at least in the early stages. Uterine myomas seem to have an effect on cytokines too. Studies have reported startling reductions in some cytokine levels like
Glycodelin etc in the mid-luteal phase of the menstrual cycle. Glycodelin is glycoprotein secreted into the uterine cavity by certain endometrial glands. It promotes the
formation of new blood vessels and suppresses natural killer cells.
Alteration in the Endo-myometrial Junction
The Endo-myometrial Junction is about 1/3rd of the myometrium and it is responsible for the generation of natural killer cells and macrophages. These two are essential in the process of embryonic implantation. However, in women with uterine myomas, there is a significant reduction in these two. This can influence IVF in particular and pregnancy in general significantly because it may result in embryo implantation failure.
Suppression of Genetic Expressions
Gene expressions like HOXA11, BTEB1 etc. modulate the receptivity of the uterus for the embryo. If there is a reduction in these gene expressions, it may lead to
failure in embryonic implantation leading to failure of IVF. Studies have shown a significant reduction in some gene’s expressions during the follicular phase in women with uterine myoma.
The impact of uterine myomas on IVF outcome is apparent. However, studies conducted on small myomas do not reflect much of the problem. It is the large
uterine myomas which may contribute to embryonic implantation failure and impact IVF outcome. Studies suggest that myomas greater than 4 cm may contribute to
implantation failures and therefore result in failed pregnancy or IVF. Since IVF can be successful only after implantation has been successful, big uterine myomas may
affect IVF to some extent.