In vitro maturation with letrozole priming: Can it be a solution for patients with cancerophobia? A pilot study

In vitro fertilization, intracytoplasmic sperm injection, in vitro maturation, and embryo culture

Infertility is a highly prevalent disease affecting 1 in 6 couples worldwide. While there are numerous treatment options available to treat infertility, in vitro fertilization (IVF) is the most successful therapy available. IVF traditionally involves superovulation of the ovaries followed by ultrasound (US)-guided oocyte retrieval, fertilization of oocytes in vitro, and culture of resultant embryos. Embryo(s) are then either transferred into the uterus or cryopreserved. There have been tremendous advances in each step of this process over the past 40 years, however, much work still remains to be done. This review discusses the history and current techniques involved in oocyte fertilization and embryo culture. Highlighted areas include conventional insemination and intracytoplasmic sperm injection (ICSI), embryo culture, and laboratory assessment. Areas of past and present research including time-lapse imaging and in vitro maturation are also discussed.

Comparison of luteal phase and follicular phase in-vitro maturation in women with oocyte maturation abnormalities

RESEARCH QUESTION

Are there differences in immature oocyte retrieval following luteal phase in-vitro maturation (IVM) compared with follicular phase IVM in women with oocyte maturation abnormalities (OMAs).

DESIGN

From January 2019 to May 2023, a retrospective cohort study at a private IVF centre included 36 women with 53 IVM cycles in Group 1 (follicular phase) and 24 women with 32 IVM cycles in Group 2 (luteal phase). Additionally, nine women had both follicular and luteal phase IVM cycles for intracycle variability analysis.

RESULTS

There were no differences in oocyte maturation stages between the groups at collection. Group 1 and Group 2 exhibited comparable median metaphase II oocyte rates per patient at 48 h after collection [40.0%, interquartile range (IQR) 0.0-66.7% versus 22.5%, IQR 0.0-52.9%] (P = 0.53). The median fertilization rate in Group 1 (66.7%, IQR 50.0-66.7%) was found to be comparable with that in Group 2 (66.7%, IQR 50.0-66.7%). There were no significant differences in the yielded embryo grades and pregnancy rates between the groups. Comparing follicular and luteal phase IVM within the same menstrual cycle in nine patients, no differences were observed in metaphase II oocyte maturation rates (P > 0.05).

CONCLUSIONS

This study found no significant differences in oocyte maturation, fertilization rate, embryo quality or pregnancy outcomes between luteal phase and follicular phase IVM in women with OMAs. These findings suggest that luteal phase IVM can be used similarly to follicular phase IVM, offering a potential avenue to enhance embryo yield for women with OMAs.

Oocyte in-vitro maturation primed with letrozole-HCG versus FSH-HCG in women with oocyte maturation abnormalities: a retrospective study

RESEARCH QUESTION

Are there differences between in-vitro maturation (IVM) primed with letrozole-human chorionic gonadotrophin (HCG) and IVM primed with FSH-HCG in women with oocyte maturation abnormalities (OMAs), defined as at least two failed IVF cycles where immature oocytes were retrieved?

DESIGN

This retrospective study was conducted at a private fertility clinic from January 2009 to April 2023. The final analysis included 75 women in Group 1 (IVM primed with FSH-HCG) and 52 women in Group 2 (IVM primed with letrozole-HCG).

RESULTS

A significantly higher median number of oocytes was obtained in Group 1 compared with Group 2 {9 [interquartile range (IQR) 1-5] versus 5 (IQR 1-18); P < 0.001}. However, no differences in oocyte maturation stage at collection were found between the groups (P > 0.05). At the end of IVM, Group 1 had 73/666 mature oocytes and Group 2 had 106/322 mature oocytes, and the median metaphase II oocyte rate per patient was higher in Group 2 [33.3% (IQR 66.7-100.0%) versus 0.0% (IQR 0.0-22.2%); P < 0.001]. Moreover, Group 2 demonstrated a higher median fertilization rate [66.7% (IQR 50.0-100.0%) versus 50.0% (IQR 0.0-66.7%); P = 0.027]. Group 2 had a higher proportion of Grade 2 embryos (58.5% versus 6.3%), and Group 1 had a higher proportion of Grade 3 embryos (93.8% vs 24.4%; P < 0.001). Notably, all pregnancies obtained in the study were in Group 2 (5 versus 0; P = 0.042).

CONCLUSIONS

IVM primed with letrozole-HCG in women with prior failed IVF cycles due to OMAs may result in mature oocytes, clinical pregnancies and live births. The effectiveness of letrozole priming for the subtypes of OMAs needs further investigation, with studies including greater numbers of cases.

TUBB8 mutations as a cause of oocyte maturation abnormalities: presentation of oocyte and embryo profiles and novel mutations

RESEARCH QUESTION

What are the embryonic profiles and oocyte maturation dynamics in patients with tubulin beta eight class VIII (TUBB8) mutations leading to oocyte maturation abnormalities (OMAS), and are pregnancies possible in this population?

DESIGN

A prospective cohort study was undertaken in a private fertility clinic between January 2019 and December 2022. Whole-exome genomic studies (WES) were performed to detect mutation types. In-vitro maturation (IVM) was compared in 18 subjects: nine with TUBB8 mutations, and nine without TUBB8 mutations to act as the control group. The distributions of oocyte maturation and embryonic development profiles were recorded. IVF and IVM outcomes of the 18 cases were evaluated. The primary outcomes were the embryonic profiles and maturation dynamics of oocytes derived from IVF or IVM in women as related to TUBB8 mutations.

RESULTS

Mutations were detected in 52 of 89 (58.4%) women who underwent WES analysis. Twelve TUBB8 mutations were detected in nine women (10.1%) with OMAS. Seven novel TUBB8 mutations were noted. Two pregnancies were obtained in women with c.535 G>A TUBB8 mutations. When comparing IVM outcomes between women with and without TUBB8 mutations, there were no differences in oocyte, embryo or pregnancy parameters (P>0.05 in all cases).

CONCLUSIONS

It is clear that further TUBB8 mutations which cause oocyte or embryonic arrest will be detected in future. Although biochemical or ectopic pregnancies may be possible in some of these women, no live births or ongoing pregnancies have been reported to date.

Unraveling the Puzzle: Oocyte Maturation Abnormalities (OMAS)

Oocyte maturation abnormalities (OMAS) are a poorly understood area of reproductive medicine. Much remains to be understood about how OMAS occur. However, current knowledge has provided some insight into the mechanistic and genetic origins of this syndrome. In this study, current classifications of OMAS syndromes are discussed and areas of inadequacy are highlighted. We explain why empty follicle syndrome, dysmorphic oocytes, some types of premature ovarian insufficiency and resistant ovary syndrome can cause OMAS. We discuss live births in different types of OMAS and when subjects can be offered treatment with autologous oocytes. As such, we present this review of the mechanism and understanding of OMAS to better lead the clinician in understanding this difficult-to-treat diagnosis.

Oocyte maturation abnormalities - A systematic review of the evidence and mechanisms in a rare but difficult to manage fertility pheneomina

A small proportion of infertile women experience repeated oocyte maturation abnormalities (OMAS). OMAS include degenerated and dysmorphic oocytes, empty follicle syndrome, oocyte maturation arrest (OMA), resistant ovary syndrome and maturation defects due to primary ovarian insufficiency. Genetic factors play an important role in OMAS but still need specifications. This review documents the spectrum of OMAS and to evaluate the multiple subtypes classified as OMAS. In this review, readers will be able to understand the oocyte maturation mechanism, gene expression and their regulation that lead to different subtypes of OMAs, and it will discuss the animal and human studies related to OMAS and lastly the treatment options for OMAs. Literature searches using PubMed, MEDLINE, Embase, National Institute for Health and Care Excellence were performed to identify articles written in English focusing on Oocyte Maturation Abnormalities by looking for the following relevant keywords. A search was made with the specified keywords and included books and documents, clinical trials, animal studies, human studies, meta-analysis, randomized controlled trials, reviews, systematic reviews and options written in english. The search detected 3,953 sources published from 1961 to 2021. After title and abstract screening for study type, duplicates and relevancy, 2,914 studies were excluded. The remaining 1,039 records were assessed for eligibility by full-text reading and 886 records were then excluded. Two hundred and twenty seven full-text articles and 0 book chapters from the database were selected for inclusion. Overall, 227 articles, one unpublished and one abstract paper were included in this final review. In this review study, OMAS were classified and extensively evaluatedand possible treatment options under the light of current information, present literature and ongoing studies. Either genetic studies or in vitro maturation studies that will be handled in the future will lead more informations to be reached and may make it possible to obtain pregnancies.