What is Assisted Hatching?

Assisted hatching is a relatively new technique used during certain IVF procedures. It is performed in order to help an embryo hatch out of its protective layering and implant into the uterus.

Assisted Hatching at Pulse Women's Hospital

During the initial stages of development, embryo is contained in a layer of proteins, known as the zona pellicuda. The zona pellicuda is designed to protect the embryo until it reaches the blastocyst stage of development. In order to successfully implant into the uterine lining, the embryo needs to hatch out of this zona pellicuda and attach to the walls of the uterus.

Sometimes, embryos have difficultly in hatching out of their protective layer. This can occur if the zona pellicuda is too thick or if the embryo does not have enough pressure from the cells to break through the layer. Assisted hatching attempts to help these embryos break out away from the zona pellicuda by creating a small hole in this outer lining.

How is Assisted Hatching Performed?

Assisted hatching is a very delicate procedure, requiring immense skill and sophisticated instrumentation. It is performed using following micromanipulation techniques.

1. By drilling with Acidified Tyrode's solution

Assisted Hatching at Pulse Women's Hospital
  The embryo is first placed in a petri-dish containing culture solution. A special pipette is then used to hold the embryo in place. The embryologist takes a hollow needle that contains an acidic solution and places it next to the zona pellucida. A tiny bit of this acidic solution is released from the needle so that it comes into contact with the zona pellicuda. This acidic solution begins to slowly digest the protective layering, creating a small hole. The embryo is then washed in culture media and transfer into the uterus solution and placed back inside an incubator

2. Mechanical opening (partial zona dissection)  by glass micro needle

Assisted Hatching at Pulse Women's Hospital
3. Laser photoablation  ; either a hole (15-20 µ) is made on the zona pellicuda or partial zona thinning is done by using laser shot.

Assisted Hatching at Pulse Women's Hospital
Assisted Hatching at Pulse Women's Hospital

This technique involves the creation of a precise gap in the zona pellicuda of selected embryos using a 1.48 micron infrared diode laser. This specifically designed laser system includes the laser, which serves as the energy source to create an opening in the zona pellicuda, and a computer which allows the operator to precisely control the laser energy output, laser pulse duration, and gap size.

The computer assisted laser method is more precise, resulting in a more consistent zona pellicuda  opening. This technique is also more quickly mastered by the embryologist. Laser assisted hatching takes less time and does not expose the embryos to potentially adverse chemicals, so embryos spend less time out of optimal culture conditions. It also requires significantly less physical manipulation of the embryos. The cumulative effect of these factors is to minimize the stress placed upon the embryo during the performance of assisted hatching.

Assisted hatching has demonstrated the potential for improving embryo implantation rates, and clinical pregnancy rates in select patient groups undergoing IVF. Infertile couples considering advanced assisted reproductive treatments should consult with their reproductive specialist regarding their candidacy for assisted hatching.

Who Can Use Assisted Hatching?

Assisted hatching techniques are required for some couples. Instead, the procedure is typically recommended for:
  • Women over the age of 37
  • Women with elevated FSH on day 3 of their menstrual cycle
  • Couples who have experienced failed IVF cycles
  • Couples whose embryos have a particularly thick zona pellicuda(>17 µ )
  • Embryos with slow cleavage rate, blastomeres number
  • Post-thaw embryos
  • Severe endometriosis
  • Unexplained infertility
  • Poor responders (
  • In vitro maturation cycle



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