Embryo Biopsy, Assisted hatching

Laser assisted hatching

  • Assisted hatching is a technique where a gap is made in the shell or “zona” of the embryo prior to the embryo transfer
  • The idea is that this small slit in the shell of the embryo improves its ability to hatch out of the shell after it forms a blastocyst

IVF hatching has been done using 3 general methods

  • Hatching with acid Tyrode’s solution – video of acid Tyrode’s embryo hatching
  • Hatching with mechanical means, such as partial zona dissection (PZD)
  • Hatching with a laser

The most commonly used method for assisted hatching over the years has been with acid Tyrode’s . However, in recent years use of a laser in IVF labs is becoming more common – and has become a useful tool for micromanipulation of embryos. However, it must be used expertly or damage to the cells could occur.

How is a laser used for IVF hatching?

As can be seen in the video (above), there is a circle of colored light that shows where the laser will fire. The beam itself is invisible and when it is pulsed we can see the effect, but can not see the laser beam itself.

A laser works by releasing energy in the embryo’s shell – thereby vaporizing or dissolving it. Because of the heat generated it must be used cautiously so that cells are not heated significantly.

In the example of embryo hatching shown in the video, the laser is pulsed 3 times to create a complete gap in the shell. The exact technique can vary based on the spot size, power settings, technique, etc.

Assisted hatching success rates

Some studies have shown that assisted hatching can improve IVF success rates as compared to cases without it. However, there are no published, well-controlled studies showing superiority of laser IVF hatching as compared to using the acid Tyrode’s method.

Why would a laser be used as the hatching method instead of other methods?

Lasers are usually used to perform trophectoderm biopsy. Therefore, when an in vitro fertilization laboratory sets up to do trophectoderm biopsy they would often get a laser and would likely start using it for their hatching procedures.

  • Assisted hatching with a laser is faster and easier to set up compared to the acid method

Assisted hatching and infertility – who should have it done?

  • There is not agreement on what the indications should be for doing assisted hatching