a grayscale of a lady justice figurine

Today I stopped my priming meds and begin a 3 day unmedicated break between priming and stims.. Now, a decision is upon us once again. It’s one I have had to make twice before, both times deciding differently (and glad that I did the last time around).

Our first cycle that yielded more embryos was one we decided to do PGT-A testing on, and we had enough embryos to test 6 (6!!!). We were very much on the fence, as we still are. The second cycle, we decided to forgo testing, instead opting to do double embryo transfers in a hope that somewhere in there we’d end up with a successful pregnancy.

I went into detail about what PGT-A testing is back in my blog post The Little Blobs that Could and Couldn’t. What I didn’t describe was this dilemma and why it exists.

PGT-A testing rules out aneuploidy, or abnormal chromosomes in the embryo. The case for is to save people time, heartache and the risk of having a child with chromosomal issues (down syndrome for example, is a chromosomal issue that can be detected). Some people prefer to avoid any risk of chromosomal issues, while others accept the risk and don’t mind. To each their own.

We learned in retrieval #1 that although it saved us time – it got rid of 4 embryos we may have otherwise transferred with no success (so they say), it did not save us heartache. We transferred two normal embryos, and one resulted in a painful and heart wrenching miscarriage at 7-8 weeks, and the other failed to implant altogether. This left us confused about whether PGT-A was right for us going forward.

The issues we face around PGT-A testing are plenty. One is that it can also discard potentially good embryos. The Aneuploid embryos are usually accurately labeled as such, but like any test, there is a margin of error. It is said to be about a 5% error rate (studies range from 1.5-5% on average, my clinic quoted 5%). (source). The second issue is damage to the embryo by biopsying it. Studies on this are quite limited, but this one explains it a bit more. One of the issues that has been found for certain types of biopsy is lower than average preterm birth weight of babies and preterm delivery. In the UK and parts of Europe, PGT-A is not commonly performed and it’s considered inconclusive. Not to mention the cost. Trying not to let that be a factor, but for many it is.

On the positive, PGT-A can narrow things down and allow us to move on quicker, to an outcome that suits our needs if we don’t have good success. If we aren’t making euploid embryos, we can get real about our methods of growing a family as I near the age of 40 (a fertility cliff, if you will).

Either way, the studies are mixed, which means the opinions of doctors and support staff are mixed, which makes the decision a super tough one. On one hand, I don’t really want to waste the time transferring embryos I am not sure about, but I also don’t want to risk that 5% to save myself some heartache. At this stage in our journey, any shot in the next year at a successful pregnancy is a shot worth taking. I am all for screening in utero, should we get there. I am excluding the idea of mosaics completely in this decision, because so far we haven’t had any, but they add a whole other range of questions about PGT-A. Some clinic will transfer them, some will not. So it adds to the complexity of testing entirely.

What did you decide to do if you’ve gone this route? How did you make that decision?

Many important convos will be had this week as we make this choice for the third time. Last time we didn’t have any embryos to freeze, so the choice turned out to be correct for us (saved us some money this way, as you have to pay up front for the PGT cycle vs not, on top of the fee per embryo at our clinic). This time, on a different protocol I really have no idea what the right choice will be.

Here’s some of the info I have found which I’ll dump on you all so you can make informed choices. For every study for, there’s a study against. (actually for every “for, there were 2+ against, despite PGT-A being so popular in North American clinics).

Studies against:

According to an analysis by Kemper, Wang, Rolnik, Mol:

“The biopsy may inflict direct damage on the embryo; the results of the biopsy, namely false positives and negatives, may be an indirect avenue of ‘damage’ to the embryo, or may reflect differences in the molecular technique utilized. Furthermore, examination of the results of only the first embryo transfer is likely to cover both indirect and direct forms of harm, as there is likely to be an increase in pregnancy rates due to the better selection of embryos. If the first embryo transferred is successful, then perhaps these harms are mitigated for the patient, but this relies on a relatively small first transfer success rate.

Mosaicism (the presence of two or more different sets of genetic material within the same embryo) may lead to potentially good quality embryos being discarded; by this mechanism, PGT-A actually removes these potentially viable embryos, whereas morphological assessment alone would allow these embryos the chance to produce an ongoing pregnancy. The reporting of embryos with a PGT-A plot falling in the mosaic range continues to be an issue, not because of the mosaicism per se, but due to the absence of solid unbiased evidence to counsel couples on the nature and destiny of these embryos. A mosaic result may be irrelevant, being confined to the placenta, or may represent true foetal mosaicism, with various degrees of clinical manifestations and significance (Kemper et al., 2019bPopovic et al., 2020). This nuance is missed when analysing only the first embryo transfer; the first embryo will likely have the highest ‘purity’ and may well not be mosaic; it is only when cumulative rates are analysed that the potential impact of mosaicism is revealed.”

Studies for: (I’ll admit these were harder to find… if anyone has any to share, feel free in the comments)
This one shows no benefit for younger IVF patients, but positive benefits for older patients:

One Comment

  1. When we tried IVF using my own eggs, we did PGT-A testing based on our ages. Now that we did donor eggs, we still tested because of the age of my husband. I will be 49 this month and he is 66. So we wanted to have the best chance possible. This entire process is pure luck and we are hoping to get on the right side of it in 2024.

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