Why you should insist that your IVF clinic does a Day 5 ( blastocyst) transfer for you

There's still a lot of confusion and controversy about whether it's best to transfer embryos on Day 3 or Day 5, especially in India. While most IVF clinics all over the world have progressed to doing blastocyst ( Day 5) transfers, many Indian IVF labs are still lagging behind, and lots of them still prefer doing Day 3 transfers - and some still continue doing obsolete Day 2 transfers.

This is not in the patient's best interest. The justification these doctors use is that the uterus is a better environment for the embryo as compared to the laboratory . They claim that if we have a good-quality embryo on Day 3 , then we should transfer as soon as possible. If it's going to become a baby, then it will do so , so why keep it outside in the incubator when it's safer inside the uterus ?

This is flawed thinking because the reality is that the best place for a day three embryo is not the uterus - it's actually the Fallopian tube. Putting it back in the uterus is not good for the embryos. In a good IVF laboratory, the best place for the embryo is the IVF lab rather than the uterus. The uterus is the right place for the embryo only when it has reached the blastocyst ( Day 5) stage. This is why all good labs prefer doing Day 5 transfers !

However, the problem is that many Indian IVF clinics have poor-quality IVF labs, with a poor rate of blastocyst formation. Because they are not willing to be honest with their patients, they make up all kinds of fairy tales that a Day 3 transfer is as good as a Day 5 transfer. Now it's not that you don't get pregnancies after Day 3 transfers - it's just that the pregnancy rate is much less as compared to Day 5 transfers. The problem is that in India it's easy to fool lots of patients a lot of the time, because patients are not well-informed and assertive.

These poor quality IVF clinics will often transfer many Day 3 embryos in order to get them to implant. This needlessly increases the risk of a high order multiple pregnancy. The advantage with a Day 5 transfer is that the ability to select the best one is much better. This is why we need to transfer only 1 -2 embryos, as a result of which the risk of a multiple pregnancy is much less. Another reason implantation rates with Day 5 transfers are better is because we have optimized the synchronization between the blastocyst and the uterus lining . This is because the best stage for an embryo when it reaches the uterus is the blastocyst stage , and not Day 3. Also, we are not wasting any embryos, because we freeze the extra blastocysts , and can use them for future cycles

The problem with these bad IVF clinics is that they know that their labs are not very good . They don't have much confidence in their ability to grow embryos to blastocysts, which is why they start taking shortcuts. Now, if you have a bad-quality lab, then I think it makes sense to put Day 3 embryos back in the uterus, because if you leave them in the incubator, they may arrest in vitro, and not form blastocysts, because the embryologist is not skilled or experienced. However, you must understand that this is a compromise. If you are going to a good-quality IVF clinic lab, then make sure that you insist on a day five transfer. This is better for everyone.

One of the fears patients have is that their embryos may look fine on Day 3, but they may not form a good-quality blastocyst on Day 5. Yes, this can happen even in a good lab - for example, in older women , or women with poor ovarian reserve, but this is actually very valuable information because it help us to diagnose that there is a problem with egg quality.

We know that the energy for embryo cell division is provided by the mitochondria which are in the cytoplasm of the egg. Today, there is no test to check the quality of these mitochondria, which is why the ability of the embryo to divide well and form a good quality blastocyst in the laboratory gives us such valuable information as to the functional competency of the eggs. If you put in a Day 3 embryo and the patient doesn't get pregnant, we are never sure what the problem was. Was it that the embryo failed to continue to develop further? Or, was there some other reason? The patient remains in the dark after suffering the horrible two-week waiting period . She is no wiser and doesn't know what to do differently the next time.

The problem is that when many Day 3 transfers fail, the doctor then conveniently labels the patient as having a recurrent implantation failure , whereas the truth is that the failure is because of poor-quality IVF lab conditions. A poor lab creates suboptimal conditions , which stress the embryo, and cause it to stop growing after the transfer, because they have been subjected to needless insults in vitro because of inexpert handling by the embryologist.

These are the patients who are then told to go in for surrogacy ! This is absolutely the wrong choice for the patient , but is far more profitable and remunerative for the clinic to offer this option.

An IVF cycle can provide invaluable diagnostic and prognostic information, and the best way to get this is by insisting that all embryos be grown to day five before they're transferred . This offers a lot of clarity, and reduces doubt because you can see the quality of your blastocysts for yourself .

What happens if you're stuck with a bad IVF lab? This is truly tragic, because you have reduced your own chances of getting pregnant. This is why you need to do your homework in advance, and make sure that your clinic does only blastocyst transfers .

While it's true that if the embryos arrests in vitro before forming a blastocyst, this can be heart breaking, because we then don't have anything to transfer. However, if it does arrest, it gives us useful information for planning your next cycle.

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Authored by : Dr Aniruddha Malpani, MD and reviewed by Dr Anjali Malpani.