Assisted zonae hatching (AZH) does not increase IVF Success in women with endometriosis

Last updated September 5, 2005
Assisted hatching or AZH is a procedure occasionally used in IVF treatment cycles. There has been great controversy regarding whether AZH increases the chances for an IVF pregnancy. Numerous studies have been conducted over the years. Some studies have suggested that there is a higher chance for pregnancy using AZH while others showed no improvement whatsoever.

The zonae is a hard protein shell that surrounds the embryo. During IVF cycles, the zonae can be seen under the microscope. Before an embryo can implant into the uterine lining, the embryo must break out of the zonae. This is known as hatching. It has been hypothesized that some embryos may have a more difficult time implanting because they cannot break out of the zonae. During IVF, the process of hatching can be assisted by either thinning the zonae or making a small gap.

Recently, a study was performed to determine whether women with endometriosis who underwent treatment with IVF would have a better chance to conceive with AZH than women who did not have AZH.

The study identified ninety women with severe endometriosis who were about to undergo an IVF treatment cycle. The women were divided randomly into two groups: those who had AZH on their embryos and those who did not have AZH. All these IVF patients were under 39 years of age and had no other identifiable cause for their infertility. The two groups of IVF patients were similar in many other factors that could affect the outcome of an IVF cycle.

The results of this study showed that there was no difference in the pregnancy rate between the group that had AZH and the group that did not have AZH. There was no difference in the chance for an embryo to implant.

In conclusion, endometriosis patients who are being treated with IVF, do not need to have AZH. AZH does not improve IVF pregnancy rates in endometriosis patients.