Assisted Hatching

Assisted hatching is a laboratory procedure which may improve the implantation rate of some embryos. The cells of an embryo are surrounded by a structure called the zona pellucida. The zona is analogous to the shell surrounding an egg. In order for an embryo to attach to the uterus and produce a pregnancy, it must “hatch” out of the zona. It is thought that the reason some embryos may not implant is that they are unable to hatch out of the zona pellucida. The assisted hatching procedure involves making a small hole in the zona pellucida. The creation of such a hole is thought to improve the chances of subsequent embryo hatching and implantation in the uterus. Assisted hatching is performed in the laboratory by the embryologist several hours before the embryo transfer procedure. Assisted hatching is performed on day 3 embryos.

The routine application of assisted hatching to all IVF patients does not appear to be beneficial. Selected patients, however, may benefit from this procedure. Older women, women with high baseline FSH levels and women who have had repeated implantation failure with IVF may benefit from assisted hatching. Embryos with a thick zona pellucida (as assessed by the embryologist on the day of transfer) may also benefit from assisted hatching, regardless of the woman’s age or FSH levels. Assisted hatching also allows the embryologist to remove fragmenting cells that may have a detrimental effect on embryo implantation. Removal of these cell fragments may improve the implantation rate of the embryos. The IVF physicians at Arkansas Fertility & Gynecology will discuss assisted hatching with each IVF couple and decide whether or not it should be performed.