Assisted hatching is a relatively small variation in the IVF procedure that has yielded improved results in older patients and those with previously failed cycles. Initial controlled trials at New York-Cornell Medical College showed a marked increase in implantation in women over age 35, and particularly over 38 or with an elevated FSH level on day three of the menstrual cycle. Couples with multiple failed IVF cycles also appear to benefit from this procedure. Assisted hatching may be helpful to these couples because their embryos lack sufficient energy to complete the “hatching” process.
Assisted Hatching Process
The assisted hatching procedure, like ICSI, is carried out by a technique known as micromanipulation. The embryos, which now contain an average of six to eight cells, are placed in small dishes and stabilized by a holding pipette. On the opposite side, a laser is used to create a small opening in the zona (the egg shell). Assisted hatching was developed in response to the theory that some women may fail multiple cycles of standard IVF because their eggs have a thicker shell and because embryos with areas of thinning of the shell were observed to be more likely to implant. By creating a minor opening in the zona the result is a greater chance of the embryo “hatching,” or shedding its shell, allowing for a better chance of implantation in the endometrium. In addition, hatched embryos implant one day early, which may allow a greater opportunity for implantation to occur, particularly if the endometrium is advanced by the ovarian stimulation.
The IVF cycle is conducted in the routine manner until the evening of the day of retrieval, when the patient is started on four days of a steroid and an antibiotic to protect the embryo from inflammatory cells. The fertilized embryos are allowed to develop until the third day following the retrieval, since the more advanced embryo is more resistant to the effects of inflammatory cells.
The addition of assisted hatching to the standard IVF protocol does add extra laboratory manipulation. There is a small risk of damage to the embryo during the micromanipulation process or at the time of transfer, and there may be a slight increase in identical twinning compared with regular IVF. We have not observed a higher rate of identical twins than with routine IVF. This may depend on making a large enough opening in the zona to prevent pinching of the embryo during the hatching process.
RPSD patient Amy Stringer, shares her story of conceiving baby Ruby through IVF. Patients like Amy, have trouble getting pregnant because of PCOS (Polycystic Ovarian Syndrome) but “high tech” treatments like IVF are helping them achieve success.