Assisted embryo hatching

 

Laser Assisted Hatching

Definition :

This technique involves the creation of a precise gap in the zona pellucida of selected embryos using a 1.48 micron infrared diode laser.

  • Contact laser / non contact laser
    • Contact laser :

      laser radiation has to be delivered directly to the zona called contact laser

      Non contact laser :

      1989- laser gamete manipulation has described in the non-contact mode. Using various wavelengths – Tadir et al.

      • It allows direct delivery of laser beam through the objectives.
      • 1.48 micron diode laser is advantageous over all other techniques as at 1.48 wave length , radiation is non mutagenic.
      • The radiation is administered in the non contact mode without embryo micromanipulation.

      Why Laser Hatching :

      This specifically designed laser system includes the laser, which serves as the energy source to create an opening in the zona pellucida and a computer which allows the operator to precisely control the laser energy output, laser pulse duration and gap size.

      Advantages :

      • 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 places upon the embryos during the performance of assisted hatching. This in turn should then translate into improved implantation and pregnancy rates.

      Principle of Laser :

      • Zona drilling of embryos would be performed with the use of UV laser microbeam. The embryos will be placed under mineral oil within 20 microlitre droplet of IVF culture medium
      • Minute laser focus adjustment will performed with the laser interface
      • Appropriate laser energy to be selected so that every single laser shot revealed a small visible impact within the zona.
      • Pulse energy of 2-5 ml at the object plane and a pulse repetition rate of 15-20 pulses will be convenient for the procedure.

      Process :

      • Infra red diode laser light focused through a microscope objective has enabled rapid non-touch micro drilling.
      • Embryos are maintained in their culture medium. Special care should be taken to open the internal side of the zona.
      • No washing of the embryos is needed after laser drilling.
      • This procedure appears to be quick, precise and is chemical free.