Why IVF treatments sometimes fail?

Why IVF treatments sometimes fail?

Several factors can lead to in vitro fertilization (IVF) failure

Many women who have already undergone a cycle will not succeed in subsequent cycles. While not all issues related to IVF failure can be corrected, others can be addressed in an effort to reduce the likelihood of failure. It is important to understand what factors are involved in each particular situation.

Age

Age is a very important factor for the success or failure of an IVF treatment. As women get older, the number of eggs in the ovaries and their quality decreases. Deterioration begins at age 30 and increases quickly after age 37. The probability of a live birth by means of IVF with own eggs is about 32% for a 35 year old woman, but only 16% for a women at the age of 40.

Embryo quality

Fertility specialists assay embryo quality on the basis of age and number of cells contained in each egg. The fertilized egg (embryo) starts as a single cell and continues dividing until it is multicellular. Three days after egg retrieval and fertilization, most specialists prefer some of the embryos to have, at least, six or seven cells. The eggs with fewer cells are less likely to be fertilized and do increase the chances of failure of IVF.

Ovarian response

In general, the more oocytes are produced in an IVF Cycle, the higher the probability of success of the cycle. The ovaries of some women, however, do not develop many follicles as they do not respond to medication used for IVF cycles, which stimulates the ovary to produce multiple eggs (one egg in each follicle develops).

You are likely to respond poorly to IVF medication if you are over 37, if you have high levels of FSH, or a reduced number of eggs are left in the ovaries. IVF is likely to fail if less than three mature follicles are produced.

Implantation problems

A pregnancy loss or miscarriage after IVF may be due to problems with the uterus, such as polyps or fibroids. Many fertility specialists, however, believe that most implantation failures are due to the arrest of the embryo, i.e. the embryo stops developing. This may be the result of a genetic defect which interferes in embryonic development.