Written by Dr Nihan Khan
The hatching of an embryo is an important step during the process of implantation. Sometimes, this process fails even in an IVF procedure. To overcome this, embryologists take the help of Assisted Hatching. This helps overcome all hurdles that come in the way of implantation and ensures a successful pregnancy.
The human egg has a protein shell surrounding it called zona pellucida. This shell has an important role in the development of an embryo. As fertilization occurs, this shell hardens, preventing the embryo from implanting prematurely. Once the embryo is ready to implant, this shell starts thinning by expanding. This creates a crack from where the embryo emerges out, leaving the protein shell behind. This is the natural process of Hatching.
In This Article
Assisted Hatching is a laboratory procedure that is mainly used as an aid to In Vitro fertilization(IVF) procedure (1). Here, a small hole is created in the zona pellucida of the embryo using various techniques. Zona pellucida is a thick membrane surrounding the developing embryo. As the embryo grows, it breaks out of this protective shell.
A small crack is made just before transferring the embryo in the uterus. This facilitates the expansion of the embryo following implantation into the uterine wall. So, this technique aims at improving the clinical pregnancy rates in those couples with prior IVF failure (2)
According to studies, this procedure increases the chances of embryo implantation in addition to allowing earlier endometrial-embryo contact (3). This greatly improves implantation efficacy and can benefit the following people.
Though, most of the time IVF treatments are successful, but, in a few women there might be chances of failure. Women with two or more unsuccessful IVF attempts can benefit from this process (4). Introducing this method to the implantation phase of IVF can greatly help in achieving a successful pregnancy.
It is a known fact that ageing reduces fertility. Women face difficulty in conceiving, as they age. In such women, even the first attempt at IVF treatment can have good results. One theory suggests that aging can lead to hardening of zona pellucida resulting in implantation failure.
Frozen embryo transfer or thawed embryos usually have hardened zona pellucida (5). This might make the natural hatching process a bit difficult.
FSH is the follicle-stimulating hormone that regular tes the menstrual cycle and stimulation of eggs in the ovaries. High levels of this hormone in the body may cause thicker zona pellucida shells (6). The thicker shell can affect the implantation process.
Embryologists use any of the following methods for achieving successful hatching. They are:
This is the most common method of hatching as it takes very little time. It is comparatively easier than the other methods and is mostly used in Day 3 or 5 embryos. It involves creating a tiny hole in the embryo or the zona pellucida shell, using a laser beam. This hatching takes place just before the transfer of the embryo.
This method was mostly in use in the past. It involves perforating the zona pellucida layer using an acidic chemical, called Tyrode solution. Using the acidic solution, a small hole is created on the embryonic surface. After perforation, washing the embryo is the next step. It is then ready to transfer to the uterus.
In this process, firstly the embryo is stabilized using a micropipette. After that, using a microneedle a hole is created in the membrane.
Here, instead of creating any hole, hydrostatic pressure is created that causes expansion of the zona pellucida. Naturally, an embryo hatches itself due to expansion of the shell .
This method involves the use of piezo technology , where an opening is made due to vibratory movements. Vibrations result in creating a conical opening in the shell.
A study suggested that laser-assisted hatching of embryos results in better chances of implantation in comparison to other methods of hatching (8)
The most common method used nowadays is Laser Assisted Hatching.
Manipulation of an embryo can result in a few possible risks. Some of them are:
There are slight chances of damage to the embryo during hatching. This can happen before, during, or after the procedure. Damage to the embryo means there will be difficulties in implantation and pregnancy.
There are high chances of identical twins or conjoined twins due to the process. This can happen if, during the process, the embryo cleaves into two. The two halves can grow and lead to twin births. Multiple births might not be pleasant for some parents.
Manipulation of embryos can increase the risk of infection. Therefore, patients are often prescribed antibiotics.
Many times, the cost of assisted hatching is already included in the IVF package in clinics where they routinely do this technique. Otherwise, the cost of this process may range between INR 15000 to 30000.
Other factors that determine the visit are the location of the fertility clinic. Usually, charges in metro cities are higher. Other factors include the number of embryos and the type of treatment.
Assisted hatching helps older women conceive successfully through IVF. This technique has proven to be an Aid to the IVF process. If you are struggling to get pregnant or having repeated failures at IVF, then don’t hesitate to discuss this with your specialist.
Normally, hatching happens six days after fertilization. In assisted hatching, if the embryo is 5 day old at the time of hatching, It will take another 1-2 days to implant.
Yes, assisted hatching increases the chances of pregnancy by increasing the chances of implantation. A successful implantation into the uterine pregnancy means a successful pregnancy.
This procedure is not recommended for all women planning IVF. It’s highly useful in women more than 37 years of age or those with prior IVF failure.
References
Fertility Cleansing – What is it, How to Do it and Top Benefits
Do Pregnancy Tests Expire – Why, When and How Accurate
AMH Testing For Ovarian Reserve – How Does it Help and How is it Done
Interpreting Endometrial Thickness – Everything You Need to Know
X-Rays While Trying To Conceive – Is it Safe to Take?
Diagnostic Tests For Female Infertility – When to Consider, Tips and List of Tests
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