Impact of letrozole co-treatment during ovarian stimulation on oocyte yield, embryo development, and live birth rate in women with normal ovarian reserve: secondary outcomes from the RIOT trial.

STUDY QUESTION: Does letrozole (LZ) co-treatment during ovarian stimulation with gonadotropins for in IVF impact follicle recruitment, oocyte number and quality, embryo quality, or live birth rate (LBR)? SUMMARY ANSWER: No impact of LZ was found in follicle recruitment, number of oocytes, quality of embryos, or LBR. WHAT IS KNOWN ALREADY: Multi-follicle stimulation for IVF produces supra-physiological oestradiol levels. LZ is an aromatase inhibitor that lowers serum oestradiol thus reducing negative feedback and increasing the endogenous gonadotropins in both the follicular and the luteal phases, effectively normalizing the endocrine milieu during IVF treatment. STUDY DESIGN, SIZE, DURATION: Secondary outcomes from a randomized, double-blind placebo-controlled trial (RCT) investigating once-daily 5 mg LZ or placebo during stimulation for IVF with FSH. The RCT was conducted at four fertility clinics at University Hospitals in Denmark from August 2016 to November 2018 and pregnancy outcomes of frozen-thawed embryo transfers (FET) registered until May 2023. PARTICIPANTS/MATERIALS, SETTING, METHODS: One hundred fifty-nine women with expected normal ovarian reserve (anti-Müllerian hormone 8-32 nmol/l) were randomized to either co-treatment with LZ (n = 80) or placebo (n = 79). In total 1268 oocytes were aspirated developing into 386 embryos, and morphology and morphokinetics were assessed. One hundred twenty-nine embryos were transferred in the fresh cycle and 158 embryos in a subsequent FET cycle. The effect of LZ on cumulative clinical pregnancy rate (CPR), LBR, endometrial thickness in the fresh cycle, and total FSH consumption was reported. MAIN RESULTS AND THE ROLE OF CHANCE: The proportion of usable embryos of retrieved oocytes was similar in the LZ group and the placebo group with 0.31 vs 0.36 (mean difference (MD) -0.05, 95% CI (-0.12; 0.03), P = 0.65). The size and number of aspirated follicles at oocyte retrieval were similar with 11.8 vs 10.3 follicles per patient (MD 1.5, 95% CI (-0.5; 3.1), P = 0.50), as well as the number of retrieved oocytes with 8.0 vs 7.9 oocytes (MD 0.1, 95% CI (-1.4; 1.6), P = 0.39) in the LZ and placebo groups, respectively. The chance of retrieving an oocyte from the 13 to 16 mm follicles at trigger day was 66% higher (95% CI (24%; 108%), P = 0.002) in the placebo group than in the LZ group, whilst the chance of retrieving an oocyte from the ≥17 mm follicles at trigger day was 50% higher (95% CI (2%; 98%), P = 0.04) in the LZ group than in the placebo group. The proportion of fertilized oocytes with two-pronuclei per retrieved oocytes or per metaphase II oocytes (MII) (the 2PN rates) were similar regardless of fertilization with IVF or ICSI with 0.48 vs 0.57 (MD -0.09, 95% CI (-0.24; 0.04), P = 0.51), and 0.62 vs 0.64 (MD -0.02, 95% CI (-0.13; 0.07), P = 0.78) in the LZ and placebo groups, respectively. However, the MII rate in the ICSI group was significantly lower with 0.75 vs 0.88 in the LZ vs the placebo group (MD -0.14, 95% CI (-0.22; -0.06), P = 0.03). Blastocysts on Day 5 per patient were similar with 1.5 vs 2.0, P = 0.52, as well as vitrified blastocysts per patient Day 5 with 0.8 vs 1.2 in (MD -0.4, 95% CI (-1.0; 0.2), P = 0.52) and vitrified blastocysts per patient Day 6 with 0.6 vs 0.6 (MD 0, 95% CI (-0.3; 0.3), P = 1.00) in the LZ vs placebo group, respectively. Morphologic evaluation of all usable embryos showed a similar distribution in 'Good', 'Fair', and 'Poor', in the LZ vs placebo group, with an odds ratio (OR) of 0.8 95% CI (0.5; 1.3), P = 0.68 of developing a better class embryo. Two hundred and ninety-five of the 386 embryos were cultured in an embryoscope. Morphokinetic annotations showed that the odds of having a high KIDscore™ D3 Day 3 were 1.2 times higher (CI (0.8; 1.9), P = 0.68) in the LZ group vs the placebo group. The CPR per transfer was comparable with 31% vs 39% (risk-difference of 8%, 95% CI (-25%; 11%), P = 0.65) in the LZ and placebo group, respectively, as well as CPR per transfer adjusted for day of transfer, oestradiol and progesterone levels at trigger, progesterone levels mid-luteal, and number of oocytes retrieved (adjusted OR) of 0.8 (95% CI (0.4; 1.6), P = 0.72). Comparable LBR were found per transfer 28% vs 37% (MD -9%, 95% CI (-26%; 9%), P = 0.60) and per randomized women 24% vs 30% (MD of -6%, CI (-22%; 8%), P = 0.60) in the LZ group and placebo group, respectively. Furthermore, 4.8 years since the last oocyte aspiration, a total of 287 of 386 embryos have been transferred in the fresh or a subsequently FET cycle, disclosing the cumulative CPR, which is similar with 38% vs 34% (MD 95% CI (8%; 16%), P = 0.70) in the LZ vs placebo group. LIMITATIONS, REASONS FOR CAUTION: Both cleavage stage and blastocyst transfer and vitrification were permitted in the protocol, making it necessary to categorize their quality and pool the results. The study was powered to detect hormonal variation but not embryo or pregnancy outcomes. WIDER IMPLICATIONS OF THE FINDINGS: The similar utilization rate and quality of the embryos support the use of LZ co-treatment for IVF with specific indication as fertility preservation, patients with previous cancer, or poor responders. The effect of LZ on mature oocytes from different follicle sizes and LBRs should be evaluated in a meta-analysis or a larger RCT. STUDY FUNDING/COMPETING INTEREST(S): Funding was received from EU Interreg for ReproUnion, Sjaelland University Hospital, Denmark, Ferring Pharmaceuticals, and Gedeon Ricther. Roche Diagnostics contributed with assays. A.P. has received grants from Ferring, Merck Serono, and Gedeon Richter, consulting fees from Preglem, Novo Nordisk, Ferring, Gedeon Richter, Cryos, & Merck A/S, speakers fees from Gedeon Richter, Ferring, Merck A/S, Theramex, & Organon, and travel support from Gedeon Richter. The remaining authors declare that they have no competing interests in the research or publication. TRIAL REGISTRATION NUMBERS: NCT02939898 and NCT02946684.

Viable acrosome-intact human spermatozoa in the ejaculate as a marker of semen quality and fertility status.

STUDY QUESTION: Is it possible, in an unbiased and clinical relevant way, to determine the number of viable acrosome-intact human spermatozoa in ejaculates and to use this as a measure of fertility chances? SUMMARY ANSWER: Image cytometry enables easy and unbiased quantification of viable acrosome-intact spermatozoa and it correlates with semen quality and fertility status. WHAT IS KNOWN ALREADY: The presence of the acrosome and its ability to respond to physiological inducers (e.g. progesterone) in the female reproductive tract at the appropriate time and place is required for fertilization. However, the available assays are labor intensive and therefore not used clinically. STUDY DESIGN, SIZE, DURATION: Washed semen samples and capacitated swim-up fractions from volunteers were used to develop the assay. Subsequently washed ejaculates from patients in fertility treatment (n = 156), proven fertile men (n = 54) and volunteers (n = 10) were assessed to evaluate the number of acrosome-intact spermatozoa in the ejaculate (acrosomal status) and compared to other semen parameters, fertility status, fertility treatments and pregnancy rates. PARTICIPANTS/MATERIALS, SETTING, METHODS: Image cytometry was used to assess the fluorescence intensity of Pisum sativum agglutinin and Propidium iodide. MAIN RESULTS AND THE ROLE OF CHANCE: The assay was validated by inducing the acrosome reaction in swim-up-purified and capacitated spermatozoa with progesterone and ionomycin, and in repeated acrosomal status measurements of washed ejaculates a small coefficient of variation (3.7%) was observed. Men with poor semen quality had fewer viable acrosome-intact spermatozoa in the ejaculate (P = 0.0012; median 32.6% vs. 49.3%). A large proportion (44%) of normozoospermic men from infertile couples had less than the observed median fraction (46%) of viable acrosome-intact spermatozoa in the ejaculate. Furthermore, the total number of viable acrosome-intact spermatozoa was significantly lower among men with male factor infertility compared to fertile men (median 35 vs. 97 mill, P = 1 × 10-7). Men from couples going through one or more ICSI cycles had significant fewer viable acrosome-intact spermatozoa than men from couples who only underwent IUI (P = 0.002; 44.4% vs. 62.0%) and the fraction of viable acrosome-intact spermatozoa appeared better than classical semen parameters in classifying whether or not couples needed ICSI. A positive, although non-significant, tendency toward ongoing pregnancy with an increasing number of viable acrosome-intact spermatozoa was observed (P = 0.2). LARGE SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: Even larger cohorts of infertile couples are needed to substantiate the clinical application of the assay in regard to estimation of fertility potential of an individual. WIDER IMPLICATIONS OF THE FINDINGS: The presented assay makes it possible to measure the number of acrosome competent spermatozoa in an ejaculate in a standardized manner and hence may serve as a new biomarker for male fertility. Few spermatozoa in an ejaculate are acrosome competent and it might be a valuable measure when evaluating male reproductive function. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by grants from the Innovation Fund Denmark. M.G. and S.K. work at ChemoMetec, which produces the image cytometer used in the study, M.G. hold shares in the company. The other authors have no conflict of interest.

Expression of membrane fusion proteins in spermatozoa and total fertilisation failure during in vitro fertilisation.

BACKGROUND: Couples increasingly experience infertility and seek help from assisted reproductive techniques to become pregnant. However, 5%-15% of the couples that are selected for in vitro fertilisation (IVF) experience a total fertilisation failure (TFF), where no zygotes develop despite oocytes and semen parameters appear to be normal. We hypothesise that TFF during IVF could be related to improper membrane fusion of gametes. OBJECTIVE: To investigate the membrane integrity and fusion proteins in spermatozoa from men in couples experiencing TFF. MATERIALS AND METHODS: A total of 33 infertile couples, 17 of which experienced TFF during IVF and 16 matched control couples with normal IVF fertilisation rates, were selected and the men re-called to deliver an additional semen sample. Proteins involved in gamete membrane fusion on spermatozoa (IZUMO1, SPESP1 and Syncytin-1) as well as O-glycosylation patterns (Tn and GALNT3), were investigated by immunofluorescence. The DNA fragmentation index, acrosomal integrity and viability of spermatozoa were determined by flow and image cytometry. RESULTS: No significant changes in the expression of GALNT3, Tn and Syncytin-1 were observed between the TFF and control groups. The fraction of spermatozoa expressing SPESP1, the median IZUMO1 staining intensity, and the percentage of viable acrosome-intact spermatozoa were significantly lower in the TFF group compared to controls. Furthermore, following progesterone-induced acrosomal exocytosis, a significant difference in the fraction of spermatozoa expressing SPESP1 and the median IZUMO1 staining intensity were observed between the control and TFF group. DISCUSSION AND CONCLUSION: Our results indicate that acrosomal exocytosis, IZUMO1 and SPESP1 expression in spermatozoa could play a crucial role in achieving fertilisation during IVF. However, the size of our cohort was quite small, and our results need to be validated with quantitative methods in larger cohorts.

In vitro fertilisation (IVF) versus intracytoplasmic sperm injection (ICSI) in patients without severe male factor infertility: study protocol for the randomised, controlled, multicentre trial INVICSI.

INTRODUCTION: Over the last decades, the use of intracytoplasmic sperm injection (ICSI) has increased, even among patients without male factor infertility. The increase has happened even though there is no evidence to support that ICSI results in higher live birth rates compared with conventional in vitro fertilisation (IVF) in cases with nonmale factor infertility. The lack of robust evidence on an advantage of using ICSI over conventional IVF in these patients is problematic since ICSI is more invasive, complex and requires additional resources, time and effort. Therefore, the primary objective of the IVF versus ICSI (INVICSI) study is to determine whether ICSI is superior to standard IVF in patients without severe male factor infertility. The primary outcome measure is first live birth from fresh and frozen-thawed transfers after one stimulated cycle. Secondary outcomes include fertilisation rate, ongoing pregnancy rate, birth weight and congenital anomalies. METHODS AND ANALYSIS: This is a two-armed, multicentre, randomised, controlled trial. In total, 824 couples/women with infertility without severe male factor will be recruited and allocated randomly into two groups (IVF or ICSI) in a 1:1 ratio. Participants will be randomised in variable block sizes and stratified by trial site and age. The main inclusion criteria are (1) no prior IVF/ICSI treatment, (2) male partner sperm with an expected count of minimum 2 million progressive motile spermatozoa following density gradient purification on the day of oocyte pick up and (3) age of the woman between 18 and 42 years. ETHICS AND DISSEMINATION: The study will be performed in accordance with the ethical principles in the Helsinki Declaration. The study is approved by the Scientific Ethical Committee of the Capital Region of Denmark. Study findings will be presented, irrespectively of results at international conferences and submitted for publication in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT04128904. Pre-results.

[Preimplantation genetic testing].

Preimplantation genetic testing (PGT) for known familial monogenetic disease (PGT-M) or structural chromosomal rearrangements (PGT-SR) has evolved into a well-established alternative to prenatal diagnosis. PGT significantly reduces the risk of a pregnancy with an affected foetus. Screening for aneuploidy (PGT-A) used as an add-on to standard IVF treatment of infertile couples is widely used internationally, although its benefit is highly debated. PGT combines genetic counselling and testing with assisted reproductive technology including ovarian stimulation, egg retrieval, and embryo biopsy, as discussed in this review.

Association between women's age and stage, morphology, and implantation of the competent blastocyst: a multicenter cohort study.

OBJECTIVE: To study if the age of women undergoing assisted reproductive technology treatment associates with stage, morphology, and implantation of the competent blastocyst. DESIGN: Multicenter historical cohort study based on exposure (age) and outcome data (blastocyst stage and morphology and initial human chorionic gonadotrophin [hCG] rise) from women undergoing single blastocyst transfer resulting in singleton pregnancy/birth. SETTING: Sixteen private and university-based facilities. PATIENT(S): In this study, 7,246 women who, between 2014 and 2018, underwent controlled ovarian stimulation (COS) or frozen-thawed embryo transfer (FET) with a single blastocyst transfer resulting in singleton pregnancy were identified. Linking data to the Danish Medical Birth Registry resulted in a total of 4,842 women with a live birth being included. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The competent blastocyst development stage (1-6), inner cell mass (A, B, C), trophectoderm (A, B, C), and initial serum hCG value. RESULT(S): Adjusted analysis of age and stage in COS treatments showed that for every 1-year increase in age there was a 5% reduced probability of the competent blastocyst assessed as being in a high stage at transfer. Comparison between hCG values in women 18-24 years and 25-29 years in both COS and FET showed significantly lower levels in the youngest women. CONCLUSION(S): The initial hCG rise was influenced by the age of the woman, with an identical pattern for hCG values in COS and FET treatments. In COS, the competent blastocyst had a reduced stage with increasing women's age.

Preparation of the endometrium and timing of blastocyst transfer in modified natural cycle frozen-thawed embryo transfers (mNC-FET): a study protocol for a randomised controlled multicentre trial.

INTRODUCTION: Despite the high number of frozen embryo transfer (FET) cycles being conducted (190 000 cycles/year) in Europe, the timing of blastocyst transfer and the use of luteal phase progesterone support in modified natural cycle FET (mNC-FET) in assisted reproductive technologies are controversial. In mNC-FET, the timing of blastocyst warming and transfer is determined according to the time of implantation in a natural cycle, aiming to reach blastocyst endometrial synchronicity. However, the optimal day of blastocyst transfer following ovulation trigger is not determined. In addition, the value of luteal phase support to maintain the endometrium remains uncertain. Thus, there is a need to identify the optimal timing of blastocyst warming and transfer and the effect of luteal phase support in a randomised controlled trial design. The aim of this randomised controlled trial is to investigate if progesterone supplementation from the early luteal phase until gestational age 8 weeks is superior to no progesterone supplementation and to assess if blastocyst warming and transfer 6 days after ovulation trigger is superior to 7 days after ovulation trigger in mNC-FET with live birth rates as the primary outcome. METHODS AND ANALYSIS: Multicentre, randomised, controlled, single-blinded trial including 604 normo-ovulatory women aged 18-41 years undergoing mNC-FET with a high-quality blastocyst originating from their first to third in vitro fertilisation/intracytoplasmic sperm injection cycle. Participants are randomised (1:1:1:1) to either luteal phase progesterone or no luteal phase progesterone and to blastocyst warming and transfer on day 6 or 7 after human chorionic gonadotropin trigger. Only single blastocyst transfers will be performed. ETHICS AND DISSEMINATION: The study is approved by the Danish Committee on Health Research Ethics (H-18025839), the Danish Medicines Agency (2018061319) and the Danish Data Protection Agency (VD-2018-381). The results of the study will be publicly disseminated. TRIAL REGISTRATION NUMBER: The study is registered in EudraCT (2018-002207-34) and on ClinicalTrials.gov (NCT03795220); Pre-results.

[Preimplantation genetic testing for aneuploidy].

This review summarises the current knowledge on preimplantation genetic testing for aneuploidy (PGT-A). Selection and transfer of euploid embryos aim to improve live birth rate (LBR) per embryo transfer, but fluorescence in situ hybridisation-based PGT-A and biopsy of cleavage stage embryos in the 2000s was a disappointment, as studies revealed a reduced LBR. Today, PGT-A includes comprehensive chromosome screening primarily of blastocyst biopsies. The benefit of PGT-A is highly debated: some suggest improved treatment outcome, while others claim, that the procedure is not cost-effective.