We routinely show patients their embryos before the transfer, and this can be quite an emotional moment for them. The commonest question they ask is - "Is this a good quality embryo?"
Of course, what they really want to know is if that embryo will become a baby, but they do realise that doctors aren't very good at predicting the fate of an embryo once we transfer it.
As a scientist , it's easy to explain to what a top quality blastocyst looks like; and that a eight-cell embryo with no fragments on Day 3 is a good quality embryo. However, from the patient's perspective , the only good embryo is one which becomes a baby !
The problem is we just cannot determine with today's technology which embryo will implant successfully and become a baby.
IVF technology has limitations , and both patients and doctors need to accept this gracefully. Thus, sometimes great looking embryos on day three will arrest on Day 4 and not form blastocysts on Day 5 in the laboratory. Conversely , we have embryos which look terrible on day three , and yet form good quality blastocysts.
The problem is that when we grade an embryo in the IVF lab, we have to depend upon eyeballing it - what does it look like ( the scientific word for which is morphology) . How many cells does it have ? Are these cells equal and regular ? Does it have fragments ? How fast does it divide ? This grading allows us to select better looking embryos as compared to the ones which don't look so good, because we know the ones with better morphology have a higher chance of implanting. However, we still can't predict the fate of an individual embryo as yet. The problem is that implantation is a complex multifactorial biological process, which is affect by many variables which we can't tease apart. This is hardly surprising, given the fact that we are trying to follow the fate of a living ball of cells which we have put back in the uterus.
This is not for lack of trying. Thus , scientists have developed additional technological tools such as PGS and CCS, where we biopsy the embryo to check its chromosomal constitution, because we know that aneuploid embryos ( those with chromosomal abnormalities ) have a lower chance of implanting. Similarly, some labs use time-lapse technology in order to get a real-time video of how the embryo develops in vitro. However, while these tools provide additional data, none of them is clinically helpful , because it still doesn't answer the patient's million-dollar question - will this embryo become a baby or not.
This can be frustrating not just for patients, but for doctors as well. Thus, we can say, "Okay, this particular embryo looks the best on day five." However , after we transfer it in the uterus, we can't track its fate, so that if doesn't implant , we can't pinpoint why it failed to do so . Did it stop dividing on Day 7 ? Or was the endometrium not receptive ?
This is what I call the " T plus 1" problem. While we can grade the embryo on that day, we don't know what will happen to it on the next day. Will it continue to grow well ? Or will it arrest ? Will the cells start fragmenting ? In the IVF lab, we have to live one day at a time, and there is no getting around this limitation as yet. In a perfect world, we would be able to grow the embryo to a baby in the lab, and then hand this over to the mother - a process called ectogenesis. However, we have not reached this level of sophistication as yet , except in science fiction
Having said this, it's still important that you have photographs of your embryos for documentation , so you can judge their quality. Other doctors can also look at your embryo photos and grade their quality. However, you do need to understand that not all good quality embryos will become a baby. Conversely, just because an embryo is of poor quality doesn't mean that it won't become a baby - and if it does, these babies are perfectly healthy and normal.
Need help in assessing the quality of your embryo ? Please send me your medical details by filling in the form at www.drmalpani.com/free-second-opinion so that I can guide you !
No comments:
Post a Comment