Reproductive outcomes from ten years of elective oocyte cryopreservation.

RESEARCH QUESTION: To assess the relationship between the number of oocytes retrieved during elective oocyte cryopreservation (EOC) cycles with various clinical, biochemical, and radiological markers, including age, body mass index (BMI), baseline anti-Müllerian hormone (AMH), antral follicle count (AFC), Oestradiol level (E2) and total number of follicles ≥ 12 mm on the day of trigger. To also report the reproductive outcomes from women who underwent EOC. METHODS: A retrospective cohort of 373 women embarking on EOC and autologous oocyte thaw cycles between 2008 and 2018 from a single London clinic in the United Kingdom. RESULTS: 483 stimulation cycles were undertaken amongst 373 women. The median (range) age at cryopreservation was 38 (26-47) years old. The median numbers of oocytes retrieved per cycle was 8 (0-37) and the median total oocytes cryopreserved per woman was 8 (0-45). BMI, E2 level and number of follicles ≥ 12 mm at trigger were all significant predictors of oocyte yield. Multivariate analysis confirmed there was no significant relationship between AFC or AMH, whilst on univariate analysis statistical significance was proven. Thirty six women returned to use their cryopreserved oocytes, of which there were 41 autologous oocyte thaw cycles undertaken. There were 12 successful livebirths achieved by 11 women. The overall livebirth rate was 26.8% per cycle. No livebirths were achieved in women who underwent EOC ≥ 40 years old, and 82% of all livebirths were achieved in women who had done so between 36 and 39 years old. CONCLUSION: Clinical, biochemical and radiological markers can predict oocyte yield in EOC cycles. Reproductive outcomes are more favourable when cryopreservation is performed before the age of 36, with lower success rates of livebirth observed in women aged 40 years and above.

Live birth rate following a euploid blastocyst transfer is not affected by double vitrification and warming at cleavage or blastocyst stage.

PURPOSE: To compare reproductive outcomes following a euploid embryo transfer, between those embryos vitrified-warmed twice to those vitrified-warmed once. METHODS: We retrospectively analysed 694 single euploid frozen embryo transfer cycles following preimplantation genetic testing for aneuploidy (PGT-A). For cycles in group 1 (N = 451), embryos were biopsied for PGT-A at blastocyst stage and vitrified. For cycles in group 2 (N = 146), embryos were vitrified at blastocyst stage, before being warmed and biopsied for PGT-A and vitrified again. For cycles in group 3 (N = 97), embryos were vitrified on day-3, before being warmed, cultured to day-5 and biopsied for PGT-A and re-vitrified. RESULTS: The pregnancy, clinical pregnancy and livebirth rate in group 2 were not statistically different to group 1 (pregnancy rate, adjusted OR 1.09, 95% CI 0.62-1.91; clinical pregnancy, aOR 0.89, 95% CI 0.58-1.37; live birth rate, aOR 0.85, 95% CI 0.56-1.28). There was also no significant difference between group 3 and group 1, with similar pregnancy rate (aOR 1.22, 95% CI 0.74-1.99), clinical pregnancy rate (aOR 1.21, 95% CI 0.75-1.96) and live birth rate (aOR 1.15, 95% CI, 0.73-1.80). There was no significant difference in miscarriage rates between all three groups. The age at the oocyte collection, embryo quality and day of biopsy were associated with pregnancy, clinical pregnancy and live birth rate. CONCLUSION: This study suggests that vitrifying and warming embryos twice at blastocyst or at cleavage and then blastocyst stage, can lead to similar reproductive outcomes to embryos vitrified-warmed once, after a single euploid embryo transfer.

Adding a low-quality blastocyst to a high-quality blastocyst for a double embryo transfer does not decrease pregnancy and live birth rate.

INTRODUCTION: The effect of embryo quality on clinical outcomes of assisted reproductive technology following a double transfer is not well defined, with some studies suggesting that a low-quality embryo transferred with a high-quality embryo decreases the live birth rate (LBR), compared with transferring a single high-quality embryo. Our study examined whether the quality of a second blastocyst transferred affects the outcome, controlling for the number of the available high-quality blastocysts (HQB). MATERIAL AND METHODS: A historical cohort study of 2346 fresh blastocyst transfers in a single fertility clinic between 2013 and 2019. The main outcomes were pregnancy, miscarriage, live birth, and multiple gestation rates. Outcomes were compared between single embryo transfers with a high-quality blastocyst (SET-H), double embryo transfers with two HQBs (DET-HH), and transfers with one high-quality and one low-quality blastocyst (DET-HL). Outcomes were also assessed between SET and DET when only low-quality blastocysts were available. RESULTS: With one HQB available, DET-HL increased LBR (adjusted odds ratio [OR] 1.65, 95% CI 1.09-2.49) compared with SET-H, but increased multiple gestation rate (aOR 23.1, 95% CI 3.0-177.6). With two HQBs available, DET-HH was associated with a higher LBR (aOR 1.62, 95% CI 1.28-2.04) and lower miscarriage rate (aOR 0.56, 95% CI 0.40-0.80), but very high twin rate (aOR 49.8, 95% CI 24.3-102.1) compared with SET-H. A SET-H with at least one or more HQB available to freeze, compared with a SET-H with no other HQB available, had a higher LBR (aOR 1.69, 95% CI 1.17-2.45). When there were no HQBs available, compared with SET-L, a DET-LL had a higher live birth (aOR 3.20, 95% CI 1.78-7.703) and twin rate (aOR 3.72 × 1010 ) and a lower miscarriage rate (aOR 0.24, 95% CI 0.10-0.58). CONCLUSIONS: When there is one HQB available, transferring an additional low-quality blastocyst would only slightly increase the LBR, but significantly increase the twin rate, therefore SET should be recommended. When two or more HQBs are available, SET-H would have a reasonably good chance of success without the very high twin rate associated with DET-HH. DET-LL when compared with SET-L, would increase the LBR, but increase the risk of multiple gestation.

The First ongoing Pregnancy Following Comprehensive Aneuploidy Assessment Using a Combined Blastocenetesis, Cell Free DNA and Trophectoderm Biopsy Strategy.

BACKGROUND: The exact origin of cell-free DNA found in spent culture media or blastocoel fluid is currently unknown but with the potential to become an improved source of DNA for chromosomal analysis than trophectoderm biopsy samples, it provides a superior representation of the fetal genetic status. However, the genetic material contained within the blastocoel cavity may be more reliable to assessment of embryo euploidy in a clinical context than trophectoderm of cell-free DNA. CASE PRESENTATION: This is the first UK case report where all three sources of DNA were analyzed in a clinical setting on 29 th January 2018 at the Centre for Reproductive and Genetic Health, London, leading to an ongoing clinical pregnancy. CONCLUSION: The experience from this case report suggests that removal of blastocoel fluid, sampling of spent culture media and trophectoderm biopsy can be carried out in parallel. Gathering genetic information from two to three independent samples of embryo DNA may provide enhanced diagnostic accuracy and may clarify cytogenetic status of mosaic embryos.

In assisted reproduction by IVF or ICSI, the rate at which embryos develop to the blastocyst stage is influenced by the fertilization method used: a split IVF/ICSI study.

PURPOSE: To compare in vitro fertilization (IVF) with intracytoplasmic sperm injection (ICSI) in regard to post-fertilization development and outcome with the purpose of ascertaining the most effective fertilization method for assisted reproduction. METHODS: A retrospective cohort study of 136 split IVF/ICSI cycles (where sibling oocytes are fertilized by two different methods using the same sperm sample). RESULTS: IVF-derived embryos developed to the blastocyst stage at a significantly faster rate than ICSI-derived embryos. There was no significant difference in fertilization or livebirth rates between the two fertilization methods. CONCLUSIONS: For patients with sperm progressive motility ≥ 1.0 × 106/ml (who usually constitute the majority of patients), no significant difference between the two fertilization methods was found in regard to fertilization rate or livebirth rate. Remaining factors influencing choice between the two methods appear to be restricted to convenience, financial considerations and concern with regard to possible perpetuation of genetically linked infertility to future generations.

Factors influencing intracytoplasmic sperm injection (ICSI) outcome in men with azoospermia.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: The management of patients with non-obstructive azoospermia (NOA) and some cases of obstructive azoospermia involves testicular sperm extraction (TESE or micro-dissection TESE) combined with intracytoplasmic sperm injection (ICSI). Several studies have investigated the effect of the male age, the cause of azoospermia, testicular histopathology, the type of sperm used, and the use of pentoxyphilline, on the ICSI cycle outcome in men with azoospermia. The present study showed that none of these factors influenced the ICSI outcome in men with azoospermia, thus once sperm is found in an azoospermic male, no other male factor seems to influence the ICSI outcome. To our knowledge this is the first study to comment on the outcome of ICSI in men with NOA based on testicular histopathology. OBJECTIVES: To access the effect of: male age, the cause of azoospermia (obstructive azoospermia vs non-obstructive azoospermia [NOA]), testicular histopathology, the type of sperm used (fresh vs frozen-thawed), and the use of pentoxyphilline on the intracytoplasmic sperm injection (ICSI) cycle outcome in men with azoospermia. To our knowledge this is the first study to comment on the outcome of ICSI in men with NOA based on testicular histopathology. PATIENTS AND METHODS: A retrospective analysis of 137 testicular sperm extraction-ICSI cycles performed between 2001-2010, involving 103 men with azoospermia, with 26 couples having repeat cycles. RESULTS: Analysis of the results did not show any statistically significant differences in the fertilization, embryo cleavage, clinical pregnancy, live birth and miscarriage rates in relation to the male age, cuase of azoospermia, testicular histopathology, type of sperm used and the use of pentoxyphilline. CONCLUSION: Once sperm is found in a man with azoospermia, no other male factor seems to influence the ICSI outcome.

Investigation of gene expression profiles before and after embryonic genome activation and assessment of functional pathways at the human metaphase II oocyte and blastocyst stage.

OBJECTIVE: To compare the oocyte versus the blastocyst transcriptome and provide data on molecular pathways before and after embryonic genome activation. DESIGN: Prospective laboratory research study. SETTING: An IVF clinic and a specialist preimplantation genetics laboratory. PATIENT(S): Couples undergoing or having completed IVF treatment donating surplus oocytes or cryopreserved blastocysts after patient consent. INTERVENTION(S): Sets of pooled metaphase II (MII) oocytes or blastocysts were processed for RNA extraction, RNA amplification, and analysis with the use of the Human Genome Survey Microarrays v2.0 (Applied Biosystems). MAIN OUTCOME MEASURE(S): Association of cell type and gene expression profile. RESULT(S): Totals of 1,909 and 3,122 genes were uniquely expressed in human MII oocytes and human blastocysts respectively, and 4,910 genes were differentially expressed between the two sample types. Expression levels of 560 housekeeping genes, genes involved in the microRNA processing pathway, as well as hormones and hormone receptors were also investigated. CONCLUSION(S): The lists of genes identified may be of use for understanding the processes involved in early embryo development and blastocyst implantation, and for identifying any dysregulation leading to infertility.