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.
🔗 Original studies are referenced in this post or within the linked Remembryo posts.
💡 Reminder: Terms underlined with a dotted black line are linked to glossary entries. Clicking these does not count toward your paywall limit.
Table of Contents
Week 1 (Mar 5 – Mar 11)
Aggressive sperm immobilization improves reproductive outcomes in patients with suboptimal semen parameters and previous ICSI fertilization failure. This study compared two methods of sperm immobilization: one was the standard method, and the other was more aggressive. The more aggressive immobilization technique was found to lead to improved fertilization rates in patients with poor fertilization.
Association of FSHR gene polymorphisms with poor ovarian response in patients undergoing IVF: A systematic review and meta-analysis. This meta-analysis combined the results of 24 studies that examined FSH receptor polymorphisms and the risk of poor ovarian response. Certain alleles were associated with increased POR risk, particularly in Asian and Caucasian populations.
Assisted reproductive technology treatment failure and the detection of intrauterine HPV through spent embryo transfer media sample. This study investigated whether intrauterine HPV infections were associated with poorer IVF outcomes. There was a lower pregnancy rate in patients with HPV infections vs those without, leading the authors to recommend screening before IVF treatment.
Intraovarian platelet-rich plasma injection and IVF outcomes in patients with poor ovarian response: a double-blind randomized controlled trial. This was a randomized controlled trial to investigate the use of intraovarian platelet-rich plasma injection in patients with poor ovarian response. PRP patients showed an increase in the number of mature eggs retrieved and pregnancy rate.
Disposables used cumulatively in routine IVF procedures could display toxicity. This study tested various consumables in the IVF lab for toxicity, such as devices for egg/sperm collection, culture dishes and embryo manipulation. Of the 53 lots tested, 8% showed toxicity when tested individually, and 35% showed toxicity when tested in combination. The authors recommend testing consumables individually as well as in combination, and to consider glass where possible.
Week 2 (Mar 12 – 18)
Does recurrent implantation failure exist? Prevalence and outcomes of five consecutive euploid blastocyst transfers in 123 987 patients. This multi-center study compared cumulative clinical pregnancy and live birth rates for over 120,000 patients who had up to five euploid transfers. After five (single) euploid transfers, the cumulative live birth rate was 98.1%, suggesting that recurrent implantation failure only represents about 2% of cases and that RIF may be overdiagnosed.
Meta-analysis of trigger timing in normal responders undergoing GnRH antagonist ovarian hyperstimulation protocol. This meta-analysis combined the results of 6 RCTs that investigated a delayed trigger vs standard trigger in patients undergoing a GnRH antagonist stimulation protocol. They found that delaying trigger time resulted in an increase in the number of eggs retrieved and a decreased fertilization rate, but no difference in the number of embryos or live birth rates.
External bending of cryodevice during vitrification leads to cryoprotectant cracks and damage to embryo blastomeres. Embryos are frozen on stick-like cryodevices, which are flexible but excessive bending of the device during freezing may damage embryos. This study found that embryos on cryodevices that were bent backwards were more likely to be damaged and had lower survival rates, and this was more severe depending on the embryo’s position on the device and as the bending force increased.
Risk factors for poor oocyte yield and oocyte immaturity after GnRH agonist triggering. This study investigated factors that were associated with egg recovery rates (how many eggs you get from >12 mm follicles) and maturity. AFC and LH level 12 hours after trigger was associated with poor egg recovery rate, and poor egg maturity was linked to BMI and AMH levels.
SARS-CoV-2 infection negatively impacts on the quality of embryos by delaying early embryonic development. This study found that patients with SARS-CoV-2 infections (COVID) had a lower number of eggs retrieved and were less likely to produce good quality embryos.
Week 3 (Mar 19 – 25)
Effects of total gonadotropin dose on embryo quality and clinical outcomes with AMH stratification in IVF cycles: a retrospective analysis of 12,588 patients. Higher gonadotropin doses might be linked to reduced egg and embryo quality. This study found that with higher gonadotropin doses there was a decrease in the rate of good quality day 3 embryos and blastocyst formation rate, along with a reduction in clinical pregnancy and live birth rates.
Effect of weight loss before in vitro fertilization in women with obesity or overweight and infertility: a systematic review and meta-analysis. This study combined the results of 6 randomized controlled trials (RCTs) involving obese or overweight women who lost weight before IVF. They found that there was no change in live birth rate, clinical pregnancy or miscarriage weight.
Long-term embryo vitrification is associated with reduced success rates in women undergoing frozen embryo transfer following a failed fresh cycle. This study compared live birth rates after transferring embryos that were frozen for different lengths of time. The highest live births were when embryos were transferred within 6 months of freezing, with lower rates after 6 months. I’ve reviewed a couple of other studies on this topic that have found a decrease over time, one that also found a decrease beyond 6 months and another that found a decrease after 6 years.
Week 4 (March 26 – April 1)
Comparison of Letrozole and Clomiphene Citrate in Pregnancy Outcomes in Patients with Polycystic Ovary Syndrome: A Systematic Review and Meta-analysis. This meta-analysis combines the results of 50 randomized controlled trials to assess the effect of letrozole and clomid on pregnancy outcomes in PCOS patients. For letrozole, they found an increase in endometrial thickness, ovulation rate and pregnancy rate, while for clomid they found an increase in the number of follicles.
Association between the systemic immune-inflammation index and GnRH antagonist protocol IVF outcomes: a cohort study. Researchers collected blood samples before egg retrieval to measure patients’ “systemic immune-inflammation index” (SII) to see if there was any connection with pregnancy outcomes. Patients with a high SII had reduced clinical pregnancy and live birth rates, and had an increased chance of early pregnancy loss.
Embryo long-term storage does not affect ART outcome: analysis of 58001 vitrified blastocysts over an 11-year period. This large study included nearly 60,000 day 5 blastocyst thaws over the course of 11 years, with embryo storage lengths of about half a month to nearly 3 years. They didn’t find any differences in live birth rates based on storage time, but did find a number of factors linked to reduced live birth rates, including blastocyst quality, BMI, number of eggs retrieved, and more. I’ve reviewed a couple of other studies on this topic that have found a decrease over time, one that also found a decrease beyond 6 months and another that found a decrease after 6 years.
Establishment and validation of a nomogram for subsequent first-cycle live births in patients diagnosed with recurrent implantation failure: a population-based analysis. This study created a type of calculator called a nomogram to predict which patients would have a live birth after being diagnosed with RIF. Their model was based on age, BMI, duration of RIF, endometrial thickness, type of embryo transferred and number of previous biochemical pregnancies.
High Dietary Inflammatory Index increases the risk of female infertility: An analysis of NHANES 2013-2018. This study aimed to compare patients’ diet inflammatory index (DII) and its link to infertility. There was an increased risk of infertility in patients in the first quartile (anti-inflammatory diet) compared to those in the fourth quartile (pro-inflammatory diet).
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