Monthly IVF research brief for January 2025

Here you’ll find a brief summary of new IVF studies for January* that I think are helpful for patients. I’ll be updating this post each week of January 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.

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Week 1 (Dec 31 – Jan 6)

Impact of previous cesarean delivery on pregnancy and neonatal outcomes in subsequent in vitro fertilization/intracytoplasmic sperm injection and single frozen-thawed embryo transfer: a historical cohort study with a large sample size. This study found that women who had a cesarean delivery in the past were less likely to get pregnant and have a live birth after IVF compared to women who had vaginal deliveries. They were also more likely to need another cesarean delivery, but there were no differences in other outcomes.

The impact of spillover and crossover effects of job stressors on pregnancy rates in couples undergoing in vitro fertilization treatments. This study examined how stress from work affects IVF success using a questionnaire, finding that women’s stress levels lowered pregnancy rates unless their partners reported low stress levels.

Association of Endometrial Thickness with Live Birth Rate: a Study Utilizing the Society for Assisted Reproductive Technology Clinic Outcome Reporting System. This study reported on IVF success rates based on endometrial thickness, finding that a thicker endometrium (up to 9mm) increased the chance of a live birth for both fresh and frozen embryo transfers.

Progesterone level in assisted reproductive technology: a systematic review and meta-analysis. This meta-analysis combined studies that examined whether progesterone levels affect pregnancy outcomes, specifically comparing day 3 and day 5 embryo transfers. They found that elevated progesterone at the time of ovulation trigger is linked to lower live birth rates for day 3 embryo transfers, but not for day 5 transfers, and the data for frozen embryo transfer cycles were too varied to draw clear conclusions.

Global, regional, and national prevalence and trends of infertility among individuals of reproductive age (15–49 years) from 1990 to 2021, with projections to 2040. This study reports a rising global prevalence of infertility among individuals aged 15–49 from 1990 to 2021, with projections indicating a continued increase through 2040.

Week 2 (Jan 7 – Jan 13)

Explainable artificial intelligence to identify follicles that optimize clinical outcomes during assisted conception. Researchers used “explainable AI” to evaluate the best time for administering a trigger shot based on follicle size, finding that 13-18 mm resulted in higher rates of mature eggs and increased live birth rates.

Whether hysteroscopy improves fertility outcomes in infertile women: a meta-analysis and systematic review. A meta-analysis combined the results of 14 studies investigating the effectiveness of of hysteroscopy. They found that hysteroscopy improves live birth and clinical pregnancy rates, with no difference in miscarriage rates.

Optimal embryo management strategies for patients undergoing antagonist protocols in IVF treatment. This study found that patients with 0-2 high-quality day 3 embryos had higher cumulative live birth rates with day 3 transfers compared to day 5/6 (blastocyst) transfers. Women with 3 or more embryos had a higher cumulative live birth rate with blastocyst stage transfers.

Effects and safety of propofol intravenous anesthesia in transvaginal oocyte retrieval on outcomes of in vitro fertilization and embryo transplantation. Propofol is commonly used as an anesthetic during the egg retrieval, and this study found that propofol had no negative impact on IVF or pregnancy outcomes.

A nomogram model to predict the high risk of lower live birth probability in young women undergoing the first IVF-ET cycle: a retrospective study. A nomogram (calculator) was developed to predict the likelihood of retrieving fewer than 10 oocytes in women ≤ 35 years old. The model, incorporating factors such as age, antral follicle count, and hormone levels, showed good predictive accuracy and reliability.

Week 3 (Jan 14 – Jan 20)

The Role of Nutrient Supplements in Female Infertility: An Umbrella Review and Hierarchical Evidence Synthesis. This “umbrella review” reviewed research on nutrient supplements for female infertility and found that taking various supplements increased live birth and clinical pregnancy rates, based on very low certainty of evidence that the authors note is “insufficient” for broad recommendation. They found that supplements had no effect on miscarriage rates, and that these supplements don’t seem to pose significant health risks.

The effects of melatonin on follicular oxidative stress and art outcomes in women with diminished ovarian reserve: a randomized controlled trial. In a small randomized controlled trial involving women with diminished ovarian reserve, the administration of melatonin improved the number of eggs retrieved, fertilization rates, and embryo quality, possibly by reducing oxidative stress in the follicles.

Oocyte maturation defect in women undergoing IVF: contributing factors and effects on mature sibling oocyte outcomes. This study investigated factors affecting low egg maturation rates in women undergoing their first IVF cycle and found that poor responders were more likely to have fewer mature eggs. Despite the low maturation rates, those with initially poor outcomes generally showed improved egg maturation in subsequent cycles.

Artificial removal of the zona pellucida at the pronuclear stage: an exploratory study to improve embryo fragmentation. This study explored the effects of artificially removing the zona at the pronuclear stage on embryo quality and blastocyst development in patients with severe early-stage embryo fragmentation. The results showed that zona removal significantly reduced fragmentation and improved the development of good-quality embryos and blastocysts.

Development of a novel calculator to predict gonadotropin dose and oocyte yield in oocyte cryopreservation cycles. This study developed a predictive model to estimate the total dose of gonadotropins required and the number of mature eggs expected in egg cryopreservation cycles. The model, which considered factors like age, hormone levels, and lifestyle, demonstrated 70% accuracy.

Successful pregnancy after preimplantation genetic testing for structural rearrangements in a couple with complex chromosome rearrangement and recurrent in vitro fertilization failures: a case report. This case report details a couple’s journey through 20 years of infertility and 10 IVF failures, leading to the discovery of a paternal complex chromosome rearrangement via high-resolution karyotype and PGT-SR, ultimately leading to a successful pregnancy and live birth.

Week 4 (Jan 21 – Jan 27)

Association between combined healthy lifestyles and infertility: a cross-sectional study in US reproductive-aged women. This study used data from a US national health survey, finding that women with 4 or 5 healthy lifestyle factors had a 59% reduced chance of infertility.

Nomogram to predict cumulative live birth rate following in vitro fertilization/intracytoplasmic sperm injection cycles in patients with endometriosis. Researchers developed a calculator to predict cumulative live birth rates for patients with endometriosis, incorporating age, whether they have adenomyosis, duration of infertility, number of fertilized eggs and the number of high quality embryos.

Sleep variability and time to achieving pregnancy: findings from a pilot cohort study of women desiring pregnancy. This pilot study found that higher variability in bed times and duration of sleep correlated with a longer time to conceive.

Novel and recurrent genetic variants associated with male and female infertility. This study used targeted next-generation sequencing to identify new and recurrent pathogenic variants in 41 patients with infertility or delayed puberty.

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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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