IVF – In-vitro Fertilization is a fertility treatment where the egg and the sperm are brought together under clinical conditions for fertilization. Once the embryo is formed, the fresh embryo is transferred back to the uterus for implantation. If the embryo attaches itself to the uterine wall, it will result in a pregnancy.
We are all aware of the importance of egg and sperm health for a successful IVF. Did you know that embryo transfer is an important step for the success of the treatment?
The IVF embryo transfer is the final step in the entire IVF process. The eggs are extracted from the woman’s ovaries, fertilized with the extracted sperm under clinical conditions, and allowed to grow into embryos. Once the embryos are formed, one or more are transferred to the uterus.
According to recent ART guidelines, not more than 3 embryos can be transferred. It is hypothesesised that transferring multiple embryos increases the chances of a successful pregnancy as at least one is expected to implant successfully. In many cases, more than one embryo will attach and result in multiple pregnancies. This is why many IVFs result in multiple births. But now a days as more advanced techniques of embryo selection are available more and more couples are operating for Single Embryo Transfer(SET).
Embryo transfer is a simple, straightforward step in the IVF process. It is non-invasive and pain-free procedure. The doctor will ask you to come with a full bladder for the ultrasound. Next with the help of the ultrasound, the doctor will pass a catheter into the womb through the cervix. The embryos are then carefully passed through the tube into the womb.
The embryo transfer can be either fresh or frozen. When the embryos form, only one or two are transferred. If there are multiple healthy embryos, you can opt to freeze them for future use. The transfer timing will differ depending on the type of embryo.
· Fresh Embryo Transfer – When the embryo is freshly fertilized, they are cultured for about two days to 5 days (blastocyst stage) after which they are safely transferred into the uterus
· Frozen Embryo Transfer – This type of embryo transfer can take about 25 days in total. The frozen embryo is thawed after getting the body ready for the transfer. The endometrial lining is artificial prepared with the help of some oral medications and once an optimum lining is achieved she will be given hormonal injections and medicines to increase her progesterone levels to ensure the uterus is ready to receive the embryo
· Blastoyst Embryo Transfer – In this method the embryo is transferred on day 5. The doctor can pick and choose the healthy embryos to transfer and freeze the rest.
· Cleavage Embryo Transfer – In this method, the embryo is transferred on day 3. This method is followed when the doctor wants to increase the survival rate of the embryo by transferring back into the uterus if they feel the embryo may not survive outside the uterus until day 5
In a natural conception, after the egg fertilizes, it takes4-5 days to travel through the fallopian tubes, to reach the uterus. In IVF, the fertilized egg – the embryo is directly transferred into the uterus to increase the chances of implantation.
Overall, it can take anywhere between 6 to 10 days after the egg retrieval, for the embryo to successfully implant. The embryo transfer can be done two to five days after egg retrieval. The time varies depending at what stage of embryo is the transfer done. The pregnancy results can be expected anytime between 10-12 days post embryo transfer.
In the case of frozen embryo transfer, the uterus is prepared first, and only after the uterine lining is thick enough is the embryo transferred. So, this may take longer.
For women below the age of 30, not more than one embryo transfer is recommended. For women between the ages of 30 and 35 years, not more than 2 embryos are recommended for transferring. For women over 35 years,3 embryos are transferred to increase the chances of a successful IVF.
As a woman’s age increases, complications in pregnancy and chances of successful pregnancy itself decrease. Since IVF is time-consuming and expensive, the doctors choose to transfer multiple embryos, so that at least one will implant and develop successfully.
The number of embryos transferred varies from practice top practice and from woman to woman. It all depends on what the fertility clinic believes is the right number and how complicated the fertility issue is. If the woman is in very good health and has excellent chances, the doctors may not transfer more than just one embryo.
For those who don’t want to undergo the entire IVF extraction and egg fertilization process every time, the fertility specialist might recommend freezing the embryos. Transferring previously frozen embryos has its own set of advantages and limitations.
No couple trying for IVF wants to hear any negative news. Here are some tips to improve your chances of a successful IVF embryo transfer:
· Avoid traveling on the same day as the in-vitro fertilization and embryo transfer. Give yourself a full day of rest before you can resume your regular activities.
· Ensure you take all your hormonal supplements and shots as prescribed and don’t miss any
· Ask your doctor to screen and choose the best embryo for transfer
· Opt for a well-equipped fertility center and a well-reputed doctor
· Avoid long hot baths right after the transfer.
1. Why does IVF fail with good embryos?