Laser Assisted HatchingDr Chinmayie R

Yet another advanced scientific solution for couples aspiring to have their baby.

There are many questions for anyone undergoing infertility treatment, especially when there is no success after repeated consultations and treatment. There are various problems associated with conceiving. A failed IVF and a negative pregnancy test aren’t the ends. Remember, it is the first step towards completing your family.

Identifying the root cause for unsuccessful IVF and correcting it is the key to success in the next cycle. There are numerous causes for negative IVF results. It could be due to abnormalities in the egg, abnormalities of the sperm or an improper selection of the embryo to transfer into the uterus or an issue in the uterus (endometrium), imbalance in the hormones, etc.

One such cause is a thickened or non-uniform zona pellucida layer around the egg.

Soon after fertilization of the egg by the male sperm, the formed embryo starts growing and eventually includes cells that make up a protective shell around the embryo, called zona pellucida. The embryo passes into the uterus after fertilization and naturally breaks out of its shell, expands, and then implants into the uterus wall, where fetal development occurs. Sometimes, the zona pellucida layer fails to break, preventing the embryo from implantation, and hence there could be a missed chance to conceive.

Assisted hatching is an assisted reproductive procedure for women who have repeated failed IVF cycles or other unidentified problems preventing pregnancy. Assisted Hatching is the procedure that helps break a thickened zona pellucida in-vitro to help with subsequent implantation.

• Women with previous failed IVF cycles. Not all women undergoing IVF would require an assisted hatching procedure. Only those with other medical conditions that reduce the chances of conceiving and experiencing an IVF procedure are recommended.

• Women with ages greater than 35 years

• Frozen embryo transfer, where the chemicals used to preserve the embryo might thicken the embryo’s outer shell.

• Increased Follicle-stimulating Hormone levels on the 2nd day of the menstrual cycle.

• Zona pellucida with a thickness of more than 15 µm (micro-meter)

Various Methods of Assisted Hatching

Mechanical methods:

• Method: This is done as a part of the IVF procedure before the embryo is transferred into the uterus. Here, the embryos are placed in an alignment steadily and the zona pellucida is partially dissected using a micro-needle.

• Method: Another method of mechanical hatching is by using hydrostatic pressure to help expand the zona pellucida layer to assist in hatching.

• Method: In this method, the embryo is subjected to vibrations created by drilling. This causes a cone-shaped opening of the zona layer.

Chemical methods:

The Embryos are arranged in an alignment similar to that of mechanical methods and are treated with a chemical called Tyrode’s solution for 40sec. Tyrode’s solution is aimed at the pile of arranged embryos with a controlled speed. This helps to make the zona pellucida layer thinner and easier to hatch naturally.

In this technique, a diode laser is used to break open a part of the zona layer. A diode laser of 1480nm wavelength is focused onto the embryo in a non-contact mode at various power settings. There are low, medium and high power settings (35mV,45mV and 55mV respectively) are used depending on the thickness of the zona pellucida layer.

Laser-Assisted Hatching comes with software that is designed for easy positioning, focus and measurement of embryos and simple alignment of the laser. The laser has three preset energy intensities that can be delivered in a single 25 ms pulse with a single click of the mouse. Low power is used for perforating very thin zona or to minimize exposure, medium power for drilling the zona of most embryos and high power for perforating thick or hard zona pellucida layer.

• Those women selected for the assisted hatching procedures are prior evaluated thoroughly about their medical history and a set of tests before initiating the process.

• The assisted hatching procedures are carried out on 3rd day after the fertilisation. Around the 5th day, embryos are ready to implant into the uterus wall.

• The technique involves focussing the laser light precisely onto the embryo to create a gap on the zona pellucida layer helping it to hatch.

• The so treated embryo is transferred back to the uterus for subsequent foetal development.

The Laser hatching procedure is considered the safest of all these hatching methods and is recommended for women with previous failed IVF procedures. Most clinicians believe this to be a better option for couples eagerly awaiting a baby. Performed under the guidance of skilled embryologists and clinicians, the process of laser-assisted hatching is reported to have minimum complications and success. There are happy couples already blessed by undergoing this procedure. Lasers have proved their effectiveness in various fields, including modern medicine. They can be a light of bliss for couples waiting for a complete family.