Monthly IVF research brief for March 2025

Here you’ll find a brief summary of new IVF studies for March* that I think are helpful for patients. I’ll be updating this post each week of March with new studies, before making a separate post for next month.

*Note that the publication dates of these studies might be outside of the indicated period, mostly because of how PubMed indexes the article and when I put this list together.

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Week 1 (Feb 25 – March 3)

Administration of dehydroepiandrosterone improves endometrial thickness in women undergoing IVF/ICSI: a systematic review and meta-analysis. This meta-analysis combined the results of 16 RCTs and found that DHEA treatment significantly improved endometrial thickness, the number of eggs retrieved and clinical pregnancy rate. The quality of evidence was rated as low to very low.

Clinical prediction models for in vitro fertilization outcomes: a systematic review, meta-analysis, and external validation. A review investigated the best model for predicting live births after IVF, finding that McLernon’s model outperformed other models. McLernon’s model was developed in 2022 and predicts the cumulative live birth rate over a maximum of 3 IVF cycles, based on age, BMI and the number of eggs collected from a first IVF cycle.

Prehypertension in male affects both semen quality and pregnancy outcomes in their first single blastocyst frozen-thawed embryo transfer cycles. This study found that prehypertension in males is associated with decreased semen quality and lower success rates, with one analysis finding that prehypertension acted as an independent risk factor for clinical pregnancy and live birth.

Embryo retention and live birth in frozen embryo transfer cycles: a cohort study. Occasionally, an embryo will get stuck in the transfer catheter during the embryo transfer. A new study, involving nearly 200 patients with retained embryos, found that this reduced the chance of a live birth.

Impact of Varicocele Embolization on DNA Fragmentation Index (DFI) in Male Infertility. This study found that varicocele embolization significantly reduces DNA fragmentation values and is associated with improved fertility outcomes in men with infertility.

Week 2 (Mar 4 – Mar 10)

Natural cycles achieve better pregnancy outcomes than artificial cycles in overweight/obese women with normal ovulatory cycles undergoing their first frozen-thawed embryo transfer: a retrospective cohort study. This study found that natural cycle FETs led to improved pregnancy rates in overweight/obese women with normal ovulatory cycles compared to medicated FETs, without an increase in obstetric complications.

Effectiveness and safety of consecutive single embryo transfer compared to double embryo transfer: results from the UK HFEA registry. This study found that two-consecutive single embryo transfers offer similar or higher live birth rates compared to double embryo transfers, while significantly reducing the risks of multiple births, preterm births, and pregnancy losses or neonatal deaths.

Real-time monitoring reveals the effects of low concentrations of volatile organic compounds in the embryology laboratory. Volatile organic compounds (VOCs) are gases emitted from various products like perfumes or plastics that can potentially harm embryos in the IVF lab. In this study, real-time monitoring detected fluctuations in VOC levels that were linked to changes in embryo quality, suggesting that even low levels of VOCs could pose a risk to embryonic development.

The dual nature of micronutrients on fertility: too much of a good thing? This study reveals that high doses of antioxidant micronutrients can disrupt redox balance and damage sperm DNA integrity in mice, suggesting that while antioxidants may improve semen quality, their supplementation should be carefully personalized to avoid adverse reproductive effects.

Primary infertile couples share more HLA alleles than expected by chance. Human Leukocyte Antigen (HLA) complexes are crucial for immune system regulation, and their genetic compatibility between partners has been implicated in infertility. This study found that primary infertile couples exhibit higher HLA similarity across certain genetic loci than would be expected by chance, suggesting a link between genetic compatibility and infertility.

Semen quality and lifespan: a study of 78 284 men followed for up to 50 years. This study reveals that men with higher total motile sperm counts (over 120 million) have a longer life expectancy by approximately 2.7 years compared to those with very low counts (0-5 million), suggesting a link between semen quality and overall longevity.

Week 3 (Mar 11 – Mar 17)

Vaginal probiotics as therapeutic adjuncts for improving embryo transfer success rates: a systematic review and meta-analysis. This meta-analysis combined the results of 6 studies and found that vaginal probiotic supplementation before embryo transfer didn’t significantly improve pregnancy, ongoing pregnancy or miscarriage rates.

Significantly increased load of hereditary cancer-linked germline variants in infertile men. This study found that infertile men have nearly a five-fold higher prevalence of disease-causing cancer gene variants compared to fertile men, demonstrating a shared genetic link between infertility and cancer risk.

First evidence of microplastics in human ovarian follicular fluid: An emerging threat to female fertility. This study is the first to detect microplastics in human ovarian follicular fluid, with correlations to FSH levels.

Cell type and region-specific transcriptional changes in the endometrium of women with RIF identify potential treatment targets. This study assessed gene expression changes in the endometrium of women with or without recurrent implantation failure, with many changes involving in immune cell regulation.

Effects of Vaginal vs. Oral Progesterone Supplementation Before Embryo Transfer on Live Birth Rates and Levels: A Randomized Trial. This study found that different routes of progesterone administration (oral vs. vaginal) before frozen embryo transfer resulted in varying plasma progesterone levels, but did not significantly influence reproductive outcomes, though higher progesterone levels correlated with ongoing pregnancies.

Week 4 (Mar 18 – Mar 24)

Cumulative live birth rates of 31 478 untested embryos from 11 463 women challenge traditional recurrent implantation failure definitions. This study measured overall (cumulative) live birth rates after up to ten transfers in women of different ages, transferring a single untested blastocyst. Cumulative rates continued to rise with each additional transfer, and didn’t plateau as other studies have found, achieving 68.3% after six transfers and 78% after ten. The continued rise in cumulative rates challenge the definition of recurrent implantation failure.

Is it justified to offer intrauterine infusion of autologous PRP in women with repeated implantation failure? This review goes over the evidence for intrauterine infusion of platelet-rich plasma (PRP) in women with recurrent implantation failure, finding that low quality and variability of the studies limit their reliability and prevent definitive conclusions.

Morphokinetic embryo behaviour in low-prognosis patients according to the POSEIDON criteria: an analysis of 3326 injected oocytes. This study evaluated embryo quality among patients with different ovarian response prognoses based on the POSEIDON criteria (which takes into account age and ovarian reserve). They found that embryo quality and pregnancy outcomes were highest among patients classified as POSEIDON group 1 (<35, AMH 1.2 ng/ml or higher).

Impact of surgeon characteristics on endometriosis surgery outcomes. The study found that surgeon volume significantly impacts postoperative outcomes in endometriosis surgery, with higher volume surgeons associated with fewer complications, lower reoperation rates, and better fertility outcomes.

The impact of Day 3 embryo quality on euploidy rate and pregnancy outcomes in PGT-A cycles: a retrospective study of 12,669 embryos. The study shows that while good-quality Day 3 embryos have a higher blastocyst formation rate compared to poor-quality ones, there is no significant difference in blastocyst euploidy rates or most pregnancy outcomes between the two groups once euploid blastocysts are transferred.

Week 5 (Mar 25 – Mar 31)

Biopsy vs comprehensive embryo/blastocyst analysis: a closer look at embryonic chromosome evaluation. Instead of just sampling a few cells for PGT-A, researchers conducted DNA sequencing on all the cells of 221 blastocysts, categorized as high-quality, low-quality, and arrested. They discovered that more than 80% of the high-quality blastocysts were euploid, and nearly 40% of the low-quality blastocysts were euploid, with chaotic aneuploidy being the primary cause of embryonic arrest.

Pregnancy outcomes with increasing maternal age, greater than 40 years, in donor oocyte cycles. A study found that live birth rate decreased for women 40-49 using donor eggs with increasing age. This suggests that age itself may have an impact on implantation, in a way that’s separate from egg quality.

Association of endometrial thickness with live birth rates among women undergoing fresh IVF, FET, and PGT cycles. Researchers investigated live birth rates based on endometrial thickness, finding that rates peaked at about 12 mm for fresh transfers and 10 mm for FET and PGT.

The impact of peak follicular estradiol levels on pregnancy outcomes in modified natural-frozen embryo transfers: an analysis including 11,321 cycles. In a study of 11,321 modified natural cycle-frozen embryo transfers, researchers found that peak follicular estradiol levels, ranging from below 154 pg/ml to above 379 pg/ml, did not significantly affect live birth rates or other reproductive outcomes.

Impact of maternal body mass index on pregnancy outcomes following frozen embryo transfer: A systematic review and meta-analysis. A meta-analysis combined the results of 17 studies, finding that maternal BMI impacts pregnancy outcomes after frozen embryo transfer, with underweight and obese women experiencing lower live birth rates.

Unraveling familial ties: elevated sperm DNA fragmentation index in infertile men and familial cancer susceptibility. In a study of 1168 men with primary couple’s infertility, researchers found that approximately 14% reported a family history of cancer, with higher sperm DNA fragmentation levels being associated with an increased likelihood of a positive cancer family history.

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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.

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