Let’s take a look at the top 5 IVF studies from 2025!
These are the top 5 posts that got the most engagement on social media or the most page views here on Remembryo. The paywall is off for this post.
These are summaries of the posts — if you want to read the full post, you can click on the picture or scroll to the end of the summary to get the link.
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🔗 Original studies are referenced in this post or within the linked Remembryo posts.
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Table of Contents
Embryos labeled aneuploid by PGT-A lead to healthy euploid twins
Embryos labeled as “aneuploid” are typically not transferred and may be discarded, under the assumption that they’re incapable of producing a healthy baby.
However, there is some evidence that these aneuploid embryos may result in healthy live births, and a new case report by Christina Tise and colleagues adds to this evidence.
In 2017, a couple had two IVF cycles that produced 4 embryos: one male euploid, and three aneuploid females.
After thorough discussion, the couple chose to transfer all four embryos, with the three aneuploid embryos transferred as a compassionate transfer.
Female twins were delivered at 36 weeks and were confirmed to be normal without any chromosomal abnormalities. They appeared to come from two of the aneuploids — either the 5AB and 4CC or from the two 4CCs — and not from the euploid male. Yes, a poor quality CC aneuploid was one of the twins!
Nearly seven years later, the twins are both healthy with no developmental issues.
So how can this happen? One potential reason is that PGT-A involves the biopsy of a few cells from the trophectoderm, which may not be representative of the ICM that becomes the fetus.
The authors acknowledge the low chance of success with aneuploid embryo transfers, but caution that excluding them could limit patients’ options, and they recommend re-evaluating selection and discard protocols that rely only on PGT-A. They also advise against multiple embryo transfers, even in cases of compassionate transfers.
The same group from Stanford was inspired by this case, and is now enrolling up to 300 patients for mosaic or aneuploid single embryo transfers in their TAME study, with full completion expected by 2039.
You can read my full summary of this post here.
Poor fertilization in IVF is usually due to sperm, not the egg
ICSI usually achieves fertilization rates of 70–80%. Still, poor fertilization in IVF (≤30%) or even fertilization failure can happen. These cases are often blamed on the egg, but it’s hard to separate egg and sperm effects.
To better understand sperm’s role, Marc Torra-Massana and colleagues studied donor egg cycles. Eggs from the same young donor were split between different patients.
The team compared what happened when the same donor’s eggs were fertilized with sperm from different men. If fertilization was poor in one cycle but good in another, the issue was linked to the sperm, not the egg.
The study found that poor fertilization was uncommon, occurring in fewer than 4% of cycles. When it did happen, most cases were tied to sperm (84%) rather than eggs or other factors (16%).
This means that while poor fertilization isn’t common, sperm problems are the main cause when it occurs. Only a small number were linked to major abnormalities on semen analysis, highlighting the need for better ways to detect hidden sperm issues.
Possible approaches include sperm DNA fragmentation testing or screening for genetic variants like PLCZ1. In some cases, treatments such as assisted oocyte activation (AOA) or alternative sperm selection methods (eg. PICSI, Zymot) may be tried, though evidence of their effectiveness is still limited.
You can read my full summary of this post here.
Poor quality embryos can still lead to live births, especially after PGT-A
Embryo quality is important for guiding transfer decisions in IVF, with poor quality blastocysts sometimes discarded because of their lower chance of success.
However, research shows that poor quality embryos can still be euploid and result in live births.
A new study by Balsam Al Hashimi and colleagues reported on euploidy rates and live birth rates for poor quality embryos.
From analysis of over 7,000 blastocysts, the researchers found that good-quality blastocysts had a higher chance of being euploid compared with fair or poor-quality blastocysts. As expected, the chance of euploidy also declined with age.
They also found that day 5 blastocysts were more likely to be euploid compared to day 6 or 7 blastocysts.
Transfer of untested poor quality embryos (mainly CC graded) led to live births in about 1 in 10 cases, compared with about 1 in 4 when PGT-A was used. Day 5 euploids had the best outcomes (compared to day 6).
For clinics that routinely discard poor quality embryos, the authors of this study suggest that testing first may be worthwhile, since euploid poor quality embryos have a higher chance of live birth compared to untested.
It’s important to note that in some poor quality embryos, there may not be enough cells to safely perform a biopsy, and in those cases the decision should be left to the embryologist’s judgment.
You can read my full summary of this post here.
Early evidence suggests rapamycin may benefit aging eggs and improve IVF outcomes
As women age, their egg quality declines, leading to fewer embryos and lower IVF success. Chromosomal issues play a big role, but other changes inside the egg may contribute as well.
A 2025 study by Jie Li and colleagues looked at one of these changes: how eggs and their support cells, called cumulus cells, manage the proteins they produce. These cells use ribosomes to build new proteins, and excessive ribosome activity could lead to damaged proteins and potentially lower egg quality.
They found that after age 34, eggs and cumulus cells showed higher ribosome activity and signs of stress. In mice, the drug rapamycin, which slows ribosome activity, partially reversed these age-related changes.
The team then tested rapamycin in IVF patients. Women who took the drug made more fertilized eggs, more embryos, and more high-quality blastocysts.
Pregnancy rates were also higher overall, mainly in patients who transferred blastocysts. There was no difference in day 3 embryo transfer outcomes.
While this is promising, these results are early and come from a small group of women who were mostly under 40, which doesn’t really line up with the study’s idea of overactive ribosomes in older eggs.
This isn’t the first study to test rapamycin in IVF, but it offers insight into the underlying biology. Larger trials are needed to report live birth outcomes, safety data, and identify which patients could benefit most.
You can read my full summary of this post here.
The problems with PGT-A: A 2025 opinion
What are some of the problems with PGT-A?
In a recent 2025 opinion article, Stéphane Viville and Mohamed Aboulghar take a hard look at PGT-A and ask whether it’s really helping couples undergoing IVF.
- Uncertain benefits. Randomized controlled trials have shown that transferring a euploid vs a patient’s best quality embryo have comparable results. These studies have been mainly done in good prognosis patients, and it’s not clear if the results would be different in other patient groups.
- Potentially viable embryos can be discarded. When PGT-A started regularly reporting mosaic results in 2015, labs were hesitant to transfer them and would discard them, a practice that still exists today to some degree. Aneuploid embryos are almost always discarded, though some have led to successful pregnancies (at a low rate).
- A single biopsy isn’t representative of the whole embryo. A typical biopsy takes 5-10 cells for PGT-A, but this isn’t sufficient to represent the rest of the blastocyst, which could be hundreds of cells. Studies have shown that rebiopsying embryos can give different results.
- PGT-A is expensive and this might limit the number of IVF cycles a couple is able to afford.
- Euploid embryos don’t always work. Factors like the uterine environment, genetic mutations and embryo quality can play a role in success.
For reasons like this, major organizations like the HFEA, ESHRE and the ASRM do not recommend the routine use of PGT-A, and Viville and Aboulghar “suggest that PGT-A should no longer be offered to infertile couples.”
In my opinion, PGT-A’s value lies in identifying aneuploid embryos so these aren’t transferred. These embryos have a high chance of miscarrying, although this is based on a limited number of studies and more research is needed.
You can read my full summary of this post here.
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About Embryoman
Embryoman (Sean Lauber) is a former embryologist and the founder of Remembryo, an IVF research and fertility education website. After working in an IVF lab in the US, he returned to Canada and now focuses on making fertility research more accessible. He holds a Master’s in Immunology and launched Remembryo in 2018 to help patients and professionals make sense of IVF research. Sean shares weekly study updates on Facebook, Instagram, and Reddit regularly. He also answers questions on Reddit or in his private Facebook group.