Assisted hatching is a micro manipulation technique performed in a lab during IVF procedure to improve the chance of pregnancy. It is also known as Zona Hatching, Drilling or Thinning. In natural conception, hatching takes place on its own. During 5-7 days of hatching the lining of the fertilised embryo is covered by a shell known as zona pellucida. After entering the uterus the outer shell of the embryo dissolves partially and the hatched embryo gets implanted in the uterus wall resulting in conception. In IVF procedure it has been found that sometimes the embryos don’t hatch on its own requiring a lab technique to help successful implant. This artificial thinning or breaching of zona is performed to improve the chances of pregnancy. This procedure is performed before embryo transfer of the patient and used for the mother and the surrogate mother.
In this assisted hatching procedure, various methods are used to make this artificial hole. The embryologist might use a micro needle to make a hole to help tear the zona so that the embryo can come out of its shell and implant easily. In chemical hatching tiny amounts of acid is used to breach the zona. In laser assisted hatching specialised laser is used to breach the zona. This is considered to be the safest method as the hole of the embryo can be made with much more precision than the needle. Apart from this, drilling and mechanical expansion of the zona is also used. In expansion the zona will get diluted like it gets in natural conception. All these procedures are meant to get over the hurdles that are preventing the embryo to stick to the uterus wall for implant. However, it requires a great deal of expertise for the embryologist to perform such procedures.
Why is assisted hatching performed?
Assisted hatching is performed where patients have history of failed IVF cycles as this technique is perceived to be helping in successful conception. IVF and Surrogacy in India has evolved a great deal in its use of technology and manipulation to achieve greater success. Women with higher age like 35 years and above would require this. Also when the embryo quality is poor, this technique is used. It is also used for frozen embryo replacements and women who has high FSH levels. Sometimes a distinct thickening of the zona is also noted by the embryologist preventing hatching.
What are the risks involved?
The risks involved are, this process might damage the embryo if not done professionally. Twin pregnancies can happen. It is very important to ask the doctor to know the reason behind such hatching if suggested by the clinic.