Understanding Laser Assisted Hatching (LAH)

Laser Assisted Hatching: Paving the Way for Embryo Hatching and Implantation

As an embryo journeys towards the blastocyst stage, it is encapsulated within the protective fortress of the zona pellucida. Successful implantation requires the embryo to “hatch” from this protective shield. However, various factors, including artificial conditions during embryo culture in the IVF lab, can cause complications in the hatching process. When not executed correctly, implantation fails, and pregnancy remains elusive. Reasons for impaired hatching can range from a “hardening” of the zona pellucida to elevated basal FSH levels, advanced maternal age, and changes in the recipient endometrial environment.

Introducing Assisted Hatching (AH)

Assisted hatching is a breakthrough laboratory technique designed to enhance embryo capability in overcoming hatching difficulties, ultimately increasing the chances of successful implantation. It has demonstrated significant improvements in pregnancy rates, especially among patients with poor prognosis who have undergone two or more previous IVF failures.

In the past, assisted hatching was performed using mechanical or chemical methods in clinical settings. However, the advent of a non-contact diode laser system has revolutionized the process. This laser system allows for precise, touch-free application through the objective. A single laser pulse lasting just milliseconds can instantaneously open the zona pellucida. This laser technology is safe, accurate, and does not negatively affect embryo development. Furthermore, it is less invasive and faster, minimizing the time embryos spend outside the incubator.

Clinical Applications of Laser Assisted Hatching

Laser assisted hatching is particularly beneficial in the following cases:

• Repeated unexplained IVF failures (at least two or more previous IVF cycles).
• Advanced maternal age, often associated with spontaneous zona hardening due to age-related endocrine changes.
• Frozen-thawed embryos that have undergone excessive in vitro culture leading to zona hardening.
• Embryos with thicker than usual zona pellucida (more than 15 μm).
• Embryos with abnormal or poor morphology.
• Embryos exhibiting cytoplasmic fragmentation.
• Embryos with a retarded developmental rate.

Advantages of Laser Assisted Hatching

• Minimal handling of embryos.
• Precise and swift control over shell opening.
• Safe and gentle, with no adverse impact on embryos.
• Widespread availability, offered under clinical guidance based on individual circumstances.