Here you’ll find a brief summary of new IVF studies for November 2023* that I think are helpful for patients. I’ll be updating this post each week of November 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 (Oct 30 – Nov 6)
Association between self-reported mobile phone use and the semen quality of young men. Men who reported using their cell phone more than 20 times a day had an associated lower sperm concentration and sperm count of 30% and 21% below the WHO reference values, with no change in sperm motility or morphology.
Sleep disorders and risk of infertility: A meta-analysis of observational studies. This meta-analysis combined the results of 8 studies relating to infertility and sleep disorders. There was no difference in patients with sleep disturbance or sleep apnea, but there was an increased risk in patients who didn’t go to bed early and wake early. If you want to check out another study that examines sleep and IVF outcomes, check out this post.
Development and validation of a nomogram model for predicting clinical pregnancy in endometriosis patients undergoing fresh embryo transfer. The chance of having a clinical pregnancy in endometriosis patients who had a fresh transfer was affected by female age, stage of endometriosis, AFC levels, AMH levels, number of eggs retrieved, and more. The researchers constructed a nomogram (a calculator) to predict the chance of clinical pregnancy based on these factors, which showed good predictive value. If you want to read a recent study on endometriosis and IVF outcomes, check out this post.
Early pregnancy bleeding after assisted reproductive technology: a systematic review and secondary data analysis from 320 patients undergoing hormone replacement therapy frozen embryo transfer. Early pregnancy bleeding (before 8 weeks) after a medicated FET occured in 47% of patients. Most bleeding consisted of spotting that lasted about 2 days. There was no difference in ongoing pregnancy rates in patients who experienced bleeding or didn’t.
Thick endometrium is associated with hypertensive disorders of pregnancy in programmed frozen-thawed embryo transfers: a retrospective analysis of 2275 singleton deliveries. Medicated FET patients with a thick endometrium (12 or more mm) had a 2-fold increase in the odds of hypertensive disorders of pregnancy (HDP) compared to patients with a thinner endometrium. The optimal thickness for reducing HDP was 9-10 mm. I have a few posts that cover endometrial thickness that you can check out here.
Week 2 (Nov 7 – Nov 11)
Risk of congenital malformations in live-born singletons conceived after intracytoplasmic sperm injection: a Nordic study from the CoNARTaS group. A recent Nordic study reveals a slight increase in major congenital malformations in babies born through ICSI compared to conventional IVF, up to 6.0% from 5.3%, compared to 4.9% of babies born without assisted reproduction. There were more respiratory and chromosomal malformations in the ICSI group compared to the IVF group, although there were very few cases overall. I have another study that looks at this same group, in terms of cancer development, that you can check out here.
Interpregnancy Interval After Clinical Pregnancy Loss and Outcomes of the Next Frozen Embryo Transfer. Women who had their FET 6 to 12 months after having a pregnancy loss were more likely to have a clinical pregnancy and a live birth, compared to women who waited <6 months. Women who waited <6 months before their next FET were at greater risk of pregnancy loss. You might also be interested in a study that looks at the best time for an FET after IVF, that you can check out here.
A cohort study on IVF outcomes in infertile endometriosis patients: the effects of rapamycin treatment. The drug rapamycin was shown to improve IVF success in endometriosis patients, with increases in the rates of fertilization, implantation and live birth, along with an increased number of mature eggs retrieved. This was linked to reduced oxidative stress levels in the follicular fluid.
Overactivation of GnRH neurons is sufficient to trigger polycystic ovary syndrome-like traits in female mice. A study in mice linked overactive GnRH neurons to PCOS-like symptoms, including disrupted reproductive cycles and hyperandrogenism. This research suggests that blocking GnRH signalling may represent a new treatment avenue for managing PCOS in humans.
Week 3 (Nov 12 – Nov 18)
Obstetric and Neonatal Outcomes After Transferring More Than One Embryo in Patients With Preimplantation Genetic Testing. Patients who transferred two euploid embryos had a higher chance of live birth compared to those who transferred only one (64.7% vs 53.2%), although the chance of multiples was much higher (46.2% vs 1.4%). In patients that transferred two euploids, there was a higher chance of adverse pregnancy outcomes, including preterm delivery and low birth weight. For ASRM recommendations on how many embryos to transfer based on age, check out this post.
Optimal Anti-Müllerian Hormone in Oocyte Donors: a national database analysis. Egg donors were grouped based on their AMH levels, and donors with high AMH (≥5 ng/mL) produced more usable embryos compared to donors with lower AMH. Between these groups, there were no differences in ongoing pregnancy rates or in the chance of getting a euploid embryo.
Paternal age does not jeopardize the live birth rate and perinatal outcomes after in vitro fertilization: an analysis based on 56,113 frozen embryo transfer cycles. Pregnancy outcomes following IVF were determined after grouping men according to their age (<25, 25-29, 30-34, 35-39, 40-44 and 45+). Women were all <36. After statistical adjustment, there were no differences in live birth, pregnancy or miscarriage rates for older men compared to men aged 25-29. There were also no differences in perinatal outcomes, such as preterm birth, low birthweight and macrosomia. To see how male age impact euploid rates, check this post.
Reproductive outcomes with delayed blastocyst development: the clinical value of day 7 euploid blastocysts in frozen embryo transfer cycles. Day 5 euploids had a higher ongoing pregnancy rate compared to day 6 and day 7 euploids (56.0% vs 45.3% and 11.1%). There were many more poor quality embryos in the day 7 euploid group compared to the other groups. Older women were more likely to produced day 7 embryos. To see another study examining day 5, 6 and 7 embryo transfer outcomes, check out this post.
Week 4 (Nov 19 – Nov 25)
Identifying a Panel of Nine Genes as Novel Specific Model in Endometriosis Noninvasive Diagnosis. A blood test was developed to assess 9 genes linked to endometriosis, which was able to help identify endometriosis patients from healthy patients with high accuracy.
The role of genetic analysis of products of conception and preimplantation genetic testing in the management of early pregnancy loss. PGT-A of products of conception after a miscarriage may help recurrent pregnancy loss patients in deciding whether or not to use PGT-A during IVF. Researchers combined PGT-A of POC along with a standard RPL workup to provide an explanation for pregnancy loss in over 90% of RPL patients.
Live birth rates in in vitro fertilization cycles with five or fewer follicles. Live birth rates were evaluated in patients with 5 or less follicles at trigger. As expected, live births were higher in patients with more follicles. This data can help patients manage expectations based on their age and follicle number.
Intra-patient analysis of individual weight gain or loss between IVF cycles: cycle now and transfer later. Patients had two IVF cycles within a span of 6 years, and either gained or lost weight. There was no difference in patients that lost weight, but patients that gained weight had more eggs retrieved and improved fertilization.
Effect of ejaculatory abstinence period on fertilization and clinical outcomes in ICSI cycles: a retrospective analysis. Men who had a longer period of ejaculatory abstinence had increased risk of abnormal fertilization (3PNs). There were no differences in blastocyst formation rates, or in cumulative pregnancy or miscarriage rates.
Week 5 (Nov 26 – Dec 4)
ESHRE guideline on the number of embryos to transfer during IVF/ICSI. The European Society of Human Reproduction and Embryology put together a great overview of factors to consider when deciding on how many embryos to transfer.
Day 7 and low-quality blastocysts: opt in or opt out? A dilemma with important clinical implications. A Fertility & Sterility “fertile battle” that puts experts on opposite sides of the debate surrounding day 7/poor quality embryo transfers. The experts discuss the pros and cons of considering these embryos.
Antibiotics prior to or at the time of embryo transfer in ART. A Cochrane review/meta-analysis that combines the results of multiple studies on the use of antibiotics before or during embryo transfer. They conclude that they are uncertain in whether or not antibiotics improve live birth rates and clinical pregnancy rates due to the limited number of studies and patients.
Mediterranean diet and female reproductive health over lifespan: a systematic review and meta-analysis. A meta-analysis combined the results of 32 studies examining the effect of the Mediterranean diet on female reproductive health. They found a reduction in adverse pregnancy outcomes like gestational diabetes and preterm birth.
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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.
