Assisted Hatching
Video Laser Assisted Hatching (Real Player required)
Assisted Hatching Overview
"Assisted hatching" (AH) is an IVF technique that involves creating a small opening in the zona pellucida surrounding the fertilized egg. Assisted hatching is performed to weaken the wall of the embryo and thus improve the likelihood of successful hatching and embryo implantation. On or around the fifth day, the zona pellucida "hatches" and the embryo, now called a blastocyst, is ready to implant. Depending on the diagnosis and patient history, we might suggest assisted hatching for a better chance of embryo implantation success with your fertility treatment. Indications for assisted hatching include advanced age, thick zona and previous IVF failures.
The zona pellucida (egg shell) has a complex structure that envelopes the egg/embryo. In nature, about two days after an embryo reaches the uterus, the zona opens and all the embryonic cells hatch out, which then try to burrow into the endometrium to establish the implantation. This is known as hatching.
The inefficiency of human in vitro fertilization (IVF) is largely due to implantation failure. Possible causes of this failure of embryos to implant successfully include:
- Genetic abnormalities of embryos
- Sub-optimal physiological and morphological development of IVF embryos
- Impaired uterine receptivity
- Abnormalities of the zona pellucida -- the presence of a thick zona or zona hardening, which may be caused by the embryo cryopreservation procedure as observed in animal research studies. These seem to occur more often in those infertile patients with elevated material age and poor prognosis.
INDICATIONS FOR ASSISTED HATCHING
- Elevated maternal age
- Elevated follicle stimulating hormone (FSH) level
- Evidence of a thickened zona pellucida of the embryos in IVF
- Unexplained implantation failure after two or more embryo transfers
Assisted hatching is generally performed on the third day of embryo culture. Briefly, the microscopic laser assisted hatching procedure is accomplished by blowing the chemical zona-drilling solution (an acidified buffer) very slowly and gently over the surface of the zona to create an opening in the zona. The zona-drilled embryos are then rinsed several times in fresh culture medium before returning them to standard culture conditions inside the IVF laboratory prior to the embryo transfer.
With this technology, state-of-the-art laser microscope equipment and the expertise of our IVF staff, we have had great success with achieving pregnancies for many couples who may have never had the opportunity for successful parenthood.
Last updated:
November 30, 2007
Authors: Dr. William Hummel and Dr. Michael Kettel