How does assisted hatching work?
Before an embryo can attach to the wall of the womb, it has to break out or ‘hatch’ from its outer layer called the zona pellucida.
It has been suggested that making a hole in or thinning this outer layer may help embryos to ‘hatch’, increasing the chances of the woman becoming pregnant in some cases.
However, assisted hatching does not improve the quality of embryos.
What is assisted hatching?
Assisted hatching is done while the embryo is in the laboratory.
Before being transferred back to the womb a hole is made in the outer layer of the embryo or it is thinned, using acid, laser or mechanical methods.
A typical procedure is:
Step 1. On day three of embryo development, the embryologist uses either weak acid in a fine glass pipette, a microlaser or a microtool to thin or cut a hole in the outer layer of the embryo.
Step 2. If weak acid was used, the embryo is washed to prevent further damage.
Step 3. Because assisted hatching thins or makes a hole in the protective outer layer around the embryo, the woman may be given antibiotics to prevent infection.
What is my chance of having a baby with assisted hatching?
Some clinicians believe that the use of assisted hatching results in higher pregnancy rates in selected cases. For example, it has been noted that in the older woman the zona pellucida around the embryo can appear to be thickened. The making of a ‘weak point’ in the zona may help implantation.
Others feel that there is no convincing evidence that it helps to improve chances of pregnancy.
If your clinic suggests this treatment, talk it through with them, asking why they are recommending it and what the benefits will be. You should also ask for any written information they may have on this treatment.
Female fertility diminishes with age, so if you are using your own eggs, on average, the younger you are, the higher your chances of success.
What are the risks of assisted hatching?
Current research suggests that this treatment is no more likely to cause an abnormality to the baby than IVF without assisted hatching. As it is only the outer layer that is affected by this procedure, the embryo should remain unharmed.
There is always some risk of damage with any procedure of this type.