Assisted hatching is a technique used primarily to assist those couples who have had one or more failed IVF cycles in the past. Often, these failed cycles have occurred as a result of the embryo failing to implant within the uterus.
For women who have a poor prognosis for their next IVF cycle, assisted hatching is likely to be suggested as an option to better the chances of a successful pregnancy.
Assisted Hatching (AH) was developed when fertility experts took notice of what IVF implantation cycles were having the most success. After it was determined that those embryos with a thinner zona pellucida (the coating of the egg) had the highest chance of implantation, this process was made in which the embryologist uses a microscope to create a small hole in this wall.
Assisted hatching is suggested for those embryos that have been found to have a thicker than normal zona pellucida in order to increase the likelihood of an implantation. This is performed on the fourth day of embryo growth when there is, on average, between 6 to 8 cells in development.
To administer an assisted hatching, the embryo is carefully removed from the incubator and held stable by a pipette. A second pipette, containing an acidified solution, is carefully applied to create a weaker zona pellucida to make implantation easier. The embryo will be rinsed to ensure there are no acidic remnants remaining before being returned to the incubator for a number of hours.
Assisted hatching has been determined to increase the chances of an implantation occurring in those patients who have been evaluated as having a poor prognosis for their Denver IVF cycle. AH is also used for those patients who have had two or more failed cycles in the past. If the embryos to be used within an IVF cycle have been determined to be of poor quality, they will likely be used in an assisted hatching. Due to the difficulty in administering the technique, the overall success chance depends largely on the skill of the Colorado reproductive embryologist.
The safety of assisted hatchings varies, largely in part due to the variety in administering the technique. One common complication that may arise is potential damage to the embryo during the weakening of the wall, with potential damage to individual embryonic cells. There is also a loose association with an increasing chance of having a pregnancy that results in monozygotic twins, due to the possibility of the zona pellucida having been thinned too much.
