Assisted hatching involves the use of mechanical or chemical thinning of the zone pellucida (outer shell) of the fertilized egg, prior to transfer into the uterus. It is believed that this outer shell becomes thicker and hardened with aging of the oocyte. As such, women of advanced age, or with an elevated FSH level on day 3, may have decreased chance for embryo implantation. The embryos of women with endometriosis and poor quality embryos may also have this problem. The technique of assisted hatching was introduced to enhance the embryos ability to hatch, and thus implant, after transfer.
The technique of assisted hatching involves measuring the thickness of the zona pellucida in embryos that are candidates for the procedure. If an embryo has not initiated the thinning process naturally, a small “window” is created chemically in the wall of the protein coat, using a dilute acidic solution pulsed onto the embryo surface through an extremely fine glass micromanipulation needle. At Advanced Fertility Services this technique involves a laser which is more effective. The embryos are then implanted normally into the uterine cavity.
You may be a candidate for assisted hatching if you are 38 years of age or older, have an elevated basal FSH level, or if you have previously had one or more IVF cycles with failure of your embryos to implant despite otherwise good results.