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Blastocyst Transfer Cultures

Blastocyst embryo transfer

blastocyst 5 day embryo transferSo, you’ve read our article on IVF and you’re all clued up. At least you think so. You’ve got your head around the sticky business of intra-cytoplasmic sperm injection and figured out the difference between follicles and fallopian tubes. But what about embryo transfer, blastocyst transfer, and the difference between the two?
Here at InterTrust Fertility, when appropriate we offer this treatment as standard.

What’s the difference between embryo transfer and blastocyst transfer?

Just to remind you (because we’re sure you’re on top of this complicated business by now), a key part of IVF involves taking ovaries from the womb, letting them have a little party with sperm in the lab dish, and then, after 2 to 5 days, the resulting embryo transplant goes back into the womb. This is what’s known as embryo transfer and has been the standard procedure for many years.
However, now the very best fertility clinics are offering something called blastocyst transfer. What is it? Well, if you’re undergoing IVF and choose to have your embryo moved to the womb at the blastocyst stage, this just means that everything happens to you occurs in exactly the same way as in embryo transfer, but just a few days later (a few days more on the sofa, if you wish).
But what is a blastocyst? Five to six days after the egg and the sperm have done the dirty deed, the embryo becomes what’s called a blastocyst. What’s different about it? So, by this stage, it has grown from just a couple of cells to up to a thousand in number, including two different types of cell. Other cell types are in progress, and a liquid-filled cavity will go on to become the amniotic fluid. The cells that will eventually form the placenta are in place, and a bunch of cells in the middle of the blastocyst – the inner cell mass – will become the fetus . It’s not particularly pretty, but it’s well on its way.
Not all embryos go on after the first few days to make it this far but those that do then lodge themselves in the lining of the womb. After blastocyst transfer during an IVF cycle, your blastocysts should hopefully do the same thing.

Why blastocyst transfer?

Between 25 and 60 per cent of your embryos will make it past the time of embryo transfer to the blastocyst stage, but they’ll be all the stronger for it. Living in an incubator for days on end is like spending all week at the gym lifting weights, and it’s partly the unnatural lab conditions that reduce their odds. Your doctor will decide which of these are the pick of the crop; the tough nuts which are dividing at the correct rate, have a single nucleus (where the DNA is), are the right size and aren’t physically damaged.
New technology means that growing blastocysts in the lab and the selection procedure itself is getting better and better. While embryologists used to gaze down a microscope, now they have ways of screening blastocysts for genetic abnormalities. This is coming in handy for couples who have a family history of certain diseases they would rather not put a child at risk of.
Finally, one or two of your very best blastocysts will be transferred to the womb and then you’ll have to cross your fingers that they pull up their socks and figure out what to do next.

What’s better? Embryo transfer or blastocyst transfer?

The statistics are clear: You have a better chance of getting pregnant by blastocyst transfer after 5 or 6 days than by standard embryo transfer after 2-5 days. This is largely because the blastocysts have had longer to develop outside of the womb and your embryologist can more easily see which ones are most likely to develop into healthy babies.
It’s also because this way of doing things is a little more in keeping with the natural processes of your body. With embryo transfer, the embryo is implanted into the womb before it would normally get there. Whereas following a natural conception, the embryo would still be in the fallopian tube at this stage. But with blastocyst transfer, it arrives in the womb at just the right time. The procedure also tends to be recommended if you’ve previously produced some good quality embryos but they failed to implant in the womb.
It’s for these reasons that blastocyst transfer can be a more reliable option than embryo transfer, especially for women under the age of 37 with a good prognosis of success from IVF. 50 to 60 per cent of women under the age of 35 become pregnant in this way – a substantially better success rate (10-20 per cent higher) than for embryo transfer.
Of course, there are drawbacks to blastocyst transfer. If you let all your embryos progress beyond the embryo transfer phase, there is a risk that none of them will develop into healthy blastocysts. And because the process has higher success rates, it also tends to result in more multiple births if you have more than one blastocyst implanted. So before you think “lovely, let’s get all the kids we want at once!”, you ought to consider the increased health risks involved.


At stands, up to 60 per cent of IVF pregnancies by blastocyst transfer result in two babies, higher than for embryo transfer. And it’s not just the ‘ouch’ factor you have to consider. Your babies will be more likely to be born prematurely and although modern medicine is very good at dealing with this, there’s an increased risk to both mother and babies. Whether you have one or more blastocysts transferred will a decision made between you and your doctor, bearing in mind the woman’s age, the quality of embryos and you and your partner’s past experience of IVF, if any. You may choose to have one or more healthy embryos frozen instead, for a future attempt at embryo transfer. SEE OUR SUCCESS RATES
Having said all that, nature sometimes does its own thing. There’s nothing to stop your single blastocyst splitting in two after it’s been implanted to give you identical twins!

Is it right for you?

At InterTrust Fertility, we believe blastocyst transfer can be a better option than embryo transfer for many couples and that is why we offer it as standard.
Many fertility clinics offer embryo transfer only, simply because they don’t have the latest technology. Most others that do provide it will charge you several hundred pounds on top of the standard IVF cost – money that we know the majority of couples can ill-afford.
InterTrust Fertility offers the latest treatments, uses the best medical techniques and technology available and doesn’t charge you more for wanting the most successful treatments. Choose us and place your hopes in the right hands.

Topic: Blastocyst Transfer

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