Did you know that we all “hatched?” No, we didn’t hatch in the traditional sense of the term (i.e. break through a shell and into this world). We actually hatched as embryos through a protective coating. Hatching is a critical step in the sequence of events that leads to implantation. The failure of an embryo to hatch may be one of many factors that lead to implantation failure and, thus, infertility.
In order to reduce the possibility of implantation failure, an embryo can be assisted to hatch. According to a Practice Committee of the Society for Reproductive Technologies (SART) and the American Society for Reproductive Medicine (ASRM), “assisted hatching involves the artificial thinning or breaching of the zona pellucida (protective coating of the embryo) and has been proposed as one technique to improve implantation and pregnancy rates following IVF.”
Assisted hatching is generally performed on day 3 embryos. However, there are risks to the embryo that can occur when performing assisted hatching. According to the Practice Committee, “the assisted hatching procedure may be associated with specific complications independent of the IVF procedure itself, including lethal damage to the embryo and damage to individual blastomeres (cells that make up a day 3 embryo) with reduction of embryo viability.” In other words, the embryo can be damaged or destroyed during the process of assisted hatching. The skill level of the embryologist performing assisted hatching can determine the rate of embryo damage. The more experienced the embryologist, the less chance there will be damage to the embryo during the procedure.
The available data studying assisted hatching showed higher clinical pregnancy and implantation rates. However, the delivery rates did not improve significantly enough to justify the use of assisted hatching in every patient.
After reviewing the available studies on assisted hatching, the Practice Committee concluded that “the available published evidence does not support the routine or universal application of assisted hatching in all IVF cycles at this time.” The Committee further stated that “assisted hatching may be clinically useful in patients with a poor prognosis, including those with ≥ 2 failed IVF cycles, poor embryo quality, and older women (≥ 38 years of age).”
Assisted hatching is not the cure all for infertility, but it could help if you fall into one of the above categories. However, you must be mindful of the risks of assisted hatching. Ask your infertility doctor if assisted hatching may be helpful in your particular infertility situation.
Source: Fertility and Sterility, Volume 90, Issue 5, Page S196-7, November 2008, Authors: Practice Committee of the Society of Assited Reproductive Technologies and American Society for Reproductive Medicine.
Dr. Lowell T. Ku, M.D. is a leading Reproductive Endocrinology and Infertility specialist at Dallas IVF, one the nation’s premiere infertility centers. Dr. Ku clarifies the many confusing terms used in the world of Infertility using straightforward explanations.
