How long does it take to transfer an embryo?

The transfer itself is a very easy procedure. It can be done with no sedation in 99.9% of the cases. It should be painless for the patient.  It can be uncomfortable like any other examination, like a pap smear in which you need to place the speculum to see the cervix. In normal conditions, the time that we need to transfer the embryo is less than 5 minutes. The transfer itself, since we usually place the catheter inside the uterus before the embryo leaves the incubator, the time that we need to transfer the embryo inside is going to be less than 30 seconds. After that, you just need a couple of hours of relative rest, and that’s it. You can start living a completely normal life.

Basically, this question is easy to answer – it doesn’t take long. However, the variation in time depends on you. So how quickly your bladder is full, how quick and easy it is to insert the speculum as well as identifying the cervix and cleaning procedure. It takes a little bit more time as to clear the mucus, clear the cervix. In the past, we used to do it straight away, however, now we are more keen on cleaning the cervical mucus. The cervical mucus is one of the important steps we should give attention to. Some use aspiration, like with pumps and negative pressure, some use just a very tiny piece of cotton wool. We take our time because the more mucus there is, the less likely it is to have a successful embryo transfer.

Having said that, I will go back to the cervical mucus issue. After identifying everything and checking that by the ultrasound scan everything is clear, we ask the embryologist to bring the embryo in the catheter. With the ultrasound guidance, it should be very easy to insert. In order to make sure that we are in the correct way and not to fiddle with a catheter filled with an embryo, we have something called ‘a two-step technique’. A catheter has an outer sheath and an inner sheath – the outer sheath is used to guide and make a secure passage from the external os of the cervix until the internal os. Once this is secure, we ask the embryologist to bring the inner catheter which contains the actual embryo. Until we have this kind of reassurance that everything is fine, this is the time that is taken between the insertion, cleaning the cervical mucus, putting the outer catheter sheath and then the embryologist is coming with the inner sheath and then inserts the actual inner sheath and then deposit the embryo. All in all, it might take anything between 10 and 20 minutes.
More than 20 minutes or up to half an hour – this is considered a very difficult embryo transfer. The main difficulties encountered will be:

1. A very tight cervix – obviously it should have been detected before. Some people have the so-called mock embryo transfer before. Some clinics insist to have a mock embryo transfer, some people do not like to have such prerequisite investigation beforehand. But as I said, the embryo transfer is within this kind of time.
2. Another thing that can make you feel that the time has elapsed even more, is when we have an embryo that is not released to the cavity and trapped in the catheter. So basically, the embryologist brings the embryo which is inside of the inner catheter and then we try to push that. We wait until the catheter is withdrawn by the embryologist and then recheck it again under the microscope. And then I get the ‘ok’ from the embryologist to tell me that the embryo has been released or has not been released. Usually, if it is one or two embryos, we have to make sure that both of them are released. Obviously, I cannot prove it from my side on the ultrasound scan because I don’t know. When we inject and we see this white-ish contrast media, this is actually the water pellet that is securing the embryo in place. So this is not the embryo that we see. A lot of people think so when we demonstrate it and you see this white-ish contrasted media on the top of the uterus. Yes, this is the fluid released, supposedly including the embryo. How do we know it for sure? We wait and that’s why we do not remove the speculum, we do not do anything except when I have the ‘ok’ from the embryologist to tell me that the embryo has been released and the catheter is empty. On some occasions – I had it and many of my colleagues had it – it’s normal to have an embryo that is not released and trapped back into the catheter. Most likely because of the cervical mucus. The cervical mucus is the one that makes like a plug – and doesn’t make the outlet of the embryo smooth. If this happens, I don’t want you to panic because this happens and it’s very easy to reload the embryo back to the catheter and then bring it back in. So this might extend the time of the embryo transfer.

As I said, the other reason is a very tight cervix or a difficult way to get in. In extreme circumstances, when you cannot just go in and negotiate the cervical length until the internal os, we abandon the embryo transfer and then we refreeze the embryo – until we sort this out. Freezing the embryo again, even after thawing, is a normal technique and this is not something out of the norm which will reduce your chances of having a successful embryo transfer later on. I think that everyone in the field has encountered this kind of difficulty. Unfortunately, sometimes you cannot predict it. However, it is very safe to ask the embryologist to freeze the embryos again until we sort out this issue of the difficult cervix. Maybe at a later stage with some dilatation or what is the recommendation for that. And once we make sure the cervix is back to normal, then we will envisage another frozen-thawed embryo transfer.

The actual insertion of the catheter and the embryo transfer itself usually doesn’t take longer than five or ten seconds but of course, the preparation takes some time and the whole visit to the clinic may take about an hour: preparation, paperwork and others. The actual procedure when the patient comes to the surgical room and is placed in the gynecological position takes about five minutes including the preparation. The speculum, the mirror, is inserted just like the regular gynecological exam. Usually we perform the transfer in two steps: at first, just the cover of the catheter, without the catheter in itself and without the embryo, is slowly, carefully and pain free inserted in the uterine cavity under the control of the ultrasound probe. When we see that the tip of this catheter cover is placed perfectly and the way is prepared for the catheter itself then, we give signal to the lab and the embryo is taken into the tip of the catheter brought and inserted through that cover – this part of the process itself takes the aforementioned 10 seconds or so. We can control the insertion of the embryo or the position of the embryo and the media which is present actually with the transfer in the uterine cavity. The catheter itself is then checked under the microscope to make sure that it’s really empty and that’s pretty much the whole procedure – so maybe five to ten minutes the whole thing and 5 to 10 seconds the transfer itself.

Usually more than 15 minutes. Again, depending on the complexity of the procedure. In 99% of women it should be very straightforward and we usually assess the route of the embryo transfer, even at the egg collection, we would assess if the uterus is in a normal position, the cavity is fine, whether we envision any problems passing the catheter. Usually on the day of embryo transfer, we don’t have any issue transferring the embryos and again , it should be very straightforward. I want to add that, even in a case that we encounter an obstruction or difficulty, we would not do the embryo transfer. We would then advise the patient “I think your embryo transfer is challenging, we may want to use some sedation in order to pass the caterer through” in which case we would freeze the embryos. We would never be in the position that we would sacrifice a very valuable embryo based on the procedure which is not going well. Sometimes in 1 or 2% of cases, you have to advise the patient that we are better off to freeze the embryo and protect the integrity of the embryo rather than just going ahead and transferring it because of the trauma that could have already been posed as a result of embryo transfer that has been attempted.

Embryo transfer is a short procedure. It should be as quick as possible because the embryo doesn’t like changes in temperature. So it should be quick. In total, together with the preparation, disinfection, etc. takes 5 minutes and the transfer itself takes 40 seconds if it goes well. If there is some problem with embryo transfer, or it is necessary to do some special preparation e.g. change the position of the uterus, then it’s longer. But these constitute only 10% of transfers. 90% of transfers are quick.

We do embryo transfer under ultrasound control. It’s very important to mention that it is difficult to say if ultrasound-guided transfers are better than non-ultrasound-guided. Studies show us that the results may be the same if the doctor is experienced in transfers. But it is better for patients to see that the position of the embryo is good. For me as well it is better to know that I’m in a good position. So we do it under ultrasound control.

We proceed this way: we put the patient in the lithotomy position, like on the gynecological chair. We have to open the vagina with a speculum, like during the Pap smear test. We have to clean the inside of the vagina with gauze and a bit of liquid. Most of the time, after this, the embryologist will give us some outer sheath of the catheter. We insert the catheter inside of the cervix, and as soon as we reach the inner opening of the uterus, we call the embryologist, and they bring the inner catheter, and we do the embryo transfer. The whole process lasts five minutes normally, not more.

Sometimes, if there’s any difficulty in the cervix, the embryo transfer may last 10 minutes. Only for patients with vaginismus, which is having contractions and fear from intercourse and gynecological exams, we advise the patient to take some station-like anesthesia.

The actual transfer of the embryo is immediate. It doesn’t take long, it’s probably a second. The moment you push the plunge, and the embryo is released inside the womb. But the total time for the procedure is a bit longer, obviously. We need the patients to be positioned properly, we need to insert the instrument, speculum, remove the mucus and cannulate the cervix.

I would say, overall, an embryo transfer takes between 15-20 minutes. We schedule them usually every 30 minutes, to give time to do the ultrasound scan as well, to look at the perfect position for the catheter and the right position for the embryo to be released in. But the actual process of releasing the embryo is pretty quick, it shouldn’t last too long at all.

During an embryo transfer procedure, a speculum is inserted into the vagina so that the cervix can be seen.  The doctor may then take some time to clean any residual medication from the vagina and cervical area before passing a very thin tube (catheter) into the cervix and uterus.  Ultrasound may be used to help the doctor see the catheter’s location.  Once the doctor is happy that they can access the uterus well, the embryologist will load the embryo into the second part of the catheter and bring it through.  The catheter containing the embryo is then fed into the uterus and released with a small volume of fluid.  The embryologist will then check the catheter under the microscope to make sure the embryo was released.  Once this is complete, you are free to rest for a few short moments before getting up to empty your bladder, get dressed and make your way home.
The procedure itself usually lasts approximately 10 minutes if straightforward, and can take longer if more complex.  Allow approximately 1 hour for the entire appointment however, as they may check that your bladder is full enough before proceeding and ask you to drink a little more, perform a blood test to check your hormone levels are sufficient and provide you with more medication to last  you up to the pregnancy test.