Micronized natural progesterone (Seidigestan®) vs GnRH antagonists for preventing the LH surge during controlled ovarian stimulation (PRO_NAT study): study protocol of a randomized clinical trial

Introduction

Progesterone-primed cycles effectively suppress the pituitary LH surge during ovarian stimulation in oocyte donors and in the infertile population. Particularly in oocyte donors, the use of synthetic progesterone (progestins) has been explored in prospective clinical trials, showing mixed results. This trial was designed to determine whether the use of micronized natural progesterone is as effective as the GnRH-antagonist protocol in terms of the number of mature oocytes (MII) retrieved in oocyte donation cycles as a primary outcome, and it also aims to explore the corresponding results in recipients as a secondary outcome.

Methods

We propose a prospective, open-label, non-inferiority clinical trial to compare a novel approach for oocyte donors with a control group, which follows the standard ovarian stimulation protocol used in our institution. A total of 150 donors (75 in each group) will be recruited and randomized using a computer algorithm. After obtaining informed consent, participants will be randomly assigned to one of two ovarian stimulation protocols: either the standard GnRH antagonist or the oral micronized natural progesterone protocol. Both groups will receive recombinant gonadotropins tailored to their antral follicle count and prior donation experiences, if any. The primary outcome is the number of mature metaphase II (MII) oocytes. Secondary measures include treatment duration, pregnancy outcomes in recipients, as well as the economic cost per MII oocyte obtained in each treatment regimen. Analyses for the primary outcome will be conducted in both the intention-to-treat (ITT) and per-protocol (PP) populations. Each donor can participate only once during the recruitment period. The estimated duration of the study is six months for the primary outcome and 15 months for the secondary outcomes.

Discussion

The outcomes of this trial have the potential to inform evidence-based adjustments in the management of ovarian stimulation protocols for oocyte donors.

Clinical trial registration

ClinicalTrials.gov, identifier, NCT05954962.

Identification of novel candidate genes associated with meiotic aneuploidy in human embryos by whole-exome sequencing

PURPOSE

To identify novel genetic variants responsible for meiotic embryonic aneuploidy.

METHODS

A prospective observational cohort study that included 29 couples who underwent trophectoderm biopsies from 127 embryos and performed whole-exome sequencing (WES) between November 2019 and March 2022. Patients were divided into two groups according to the expected embryo aneuploidy rate based on maternal age.

RESULTS

After variant filtering in the WES analysis of 58 patients/donors, five heterozygous variants were identified in female partners from the study group that had an impact on embryo aneuploidy. Additionally, a slowdown in embryo development and a decrease in the number of blastocysts available for biopsy were observed in the study group embryos.

CONCLUSION

This study has identified new candidate genes and variants not previously associated with meiotic embryo aneuploidy, but which are involved in important biological processes related to cell division and chromosome segregation. WES may be an efficient tool to identify patients with a higher-than-expected risk of embryo aneuploidy based on maternal age and allow for individualized genetic counselling prior to treatment.

P-594 mRNA COVID-19 vaccine does not influence performance during oocyte donation cycles

Study question

What is the effect of mRNA SARS-CoV-2 vaccines on oocyte donors regarding oocyte quality, embryo development and clinical outcomes?

Summary answer

Oocyte quality, fertilization, blastocyst formation, embryo quality and pregnancy rates were similar following donors' mRNA SARS-CoV-2 vaccination compared to previous oocyte donation cycles.

What is known already

The severe acute respiratory syndrome Coronavirus 2 (SARS–CoV-2) infection, urged scientists to develop safe and effective vaccines. During the ongoing pandemic, the scientific community has promoted vaccination programs to reduce morbidity and mortality.

While it has been suggested that SARS–CoV-2 infection might impact fertility, limited evidence shows that vaccination has no influence on sperm parameters, follicular steroidogenesis, or oocyte quality and only one study reported no effects on fertilization or top-quality embryos rate in vaccinated patients undergoing IVF. There is a paucity of evidence with regards to younger population undergoing ovarian stimulation.

Study design, size, duration

This prospective, multicentre cohort study evaluated 32 oocyte donors with two controlled and similar ovarian stimulation, before and after complete SARS-CoV-2 vaccination, between November 2020 and January 2022. A total of 64 oocyte recipient cycles were analysed equally separately into these two groups. Severe male factor was excluded.

Participants/materials, setting, methods

Complete SARS-CoV-2 vaccination of the oocyte donor made the difference between the two groups of recipients analysed. The time frame between the previous ovarian stimulation and the vaccination was lower than 8 months. We evaluated and compared the rates of matured eggs (metaphase II, MII), the fertilization and blastocyst formation rates, blastocyst quality (A/B ASEBIR categories), positive pregnancy test and clinical pregnancy rates in both groups of recipients. The statistical analysis was performed using SPSS.

Main results and the role of chance

The average number of MII collected were similar before and following vaccination (12.23 vs 12.91, p = 0.198, respectively). In recipients, the outcomes with regards to fertilization rate (81.4% vs 77.3% p = 0.210), blastocyst formation rate (60.2% vs 61.5%, p = 0.771) and high-quality blastocysts (quality A: 31.1% vs 36.4% and quality B: 29.0% vs 25.1%, p = 0.430) did not differ statistically between the control group (n = 32, pre-vaccination) and the study group (n = 32, post-vaccination), respectively.

Furthermore, regarding clinical outcomes, there were not statistically differences in pregnancy rates (64.0% vs 77.4%, p = 0.269) or clinical pregnancy rates (60.0% vs 64.5%, p = 0.729) before and after vaccination respectively.

Limitations, reasons for caution

Our encouraging results should be interpreted with caution due to the small sample size and the short period of follow-up. Larger controlled trials are needed to corroborate our findings as the countries continue making forward with the vaccination campaign.

Wider implications of the findings

The present study suggests no influence of mRNA SARS-CoV2 vaccines on donor oocyte cycles, reflecting no detrimental effects on the assisted reproduction outcomes. The safety of SARS-CoV-2 vaccination concerning IVF cycles is encouraging for the medical community and the health of our patients.

Trial registration number

Not Applicable

O-099 The use of cumulus cells (CCs) to select spermatozoa for intracytoplasmic sperm injection improves blastocyst development and quality

Study question

Is there a role for sperm selection based on the capacity to pass through cumulus oophorous column in improving the laboratory outcomes in ICSI cycles?

Summary answer

A higher rate of blastocyst formation and quality are obtained with the use of CCs to select spermatozoa for ICSI compared to conventional density gradients.

What is known already

The sperm selection for ICSI is an operator-dependent procedure based on sperm morphology and motility. ICSI bypasses all natural barriers of sperm selection, which may impact embryo development.

During natural fertilization, only the spermatozoa that pass-through cumulus cells will have the chance to fertilize the egg. Spermatozoa capable of traverse COCs have better morphology, higher chromatin integrity and greater acrosomal reaction. Hyaluronic acid is an important component of these cells and plays a key role in the selection of spermatozoa with intact DNA. However, there is scarce data regarding this selection method for ICSI on the development of the embryo.

Study design, size, duration

This is a prospective randomized sibling oocyte pilot study (February-December 2021). A total of 996 metaphase II (MII) oocytes were randomized into two groups. In the control group (Group 0, n = 489 MII), ICSI was performed with sperm selected by conventional density gradients. In the study group (Group 1, n = 507 MII) the oocytes were microinjected with sperm selected through CCs. The main outcome was blastocyst formation rate and quality. Reproductive results were analyzed as secondary outcomes.

Participants/materials, setting, methods

Ninety-eight couples undergoing ICSI (private center) with ≥6 fresh own MII obtained after ovarian stimulation, embryo culture until blastocyst stage and ejaculated sperm samples were included in the study.

All seminal samples were processed using density gradients and those in the study group were additionally passed through CCs (the patient's own CCs were used in all cases).

Fertilization and day 5 blastocyst formation rates were assessed. Embryo quality was scored according to Gardner's criteria.

Main results and the role of chance

Data was similar with regards to cause of infertility, maternal age (36.47 vs 36.63 y.o.), sperm count (60.53 vs 58.25 mill/ml) and progressive motility (57.45 vs 57.50%) between group 0 vs 1, respectively.

Fertilization rate was similar between groups (74.0% vs 78.7%; p = 0.419. Group 0 vs 1, respectively). However, the blastocyst formation rate was significantly higher in the study group compared to control (70.9% vs 60.1%; p = 0.002). In addition, high-quality blastocyst rate was significantly higher in the CCs compared to the control group (49.6% vs 38.5%; p = 0.003). After the analysis of 145 treatments (131 frozen vs 14 fresh transfers) the cumulative clinical pregnancy rate in the study group was 47.2%, higher than in the control group (32.1%), but without reaching statistical difference (p = 0.07).

Limitations, reasons for caution

This is an exploratory study, aimed to evaluate the effectiveness of CCs as a more “physiologic” selection of spermatozoa for ICSI treatments in terms of laboratory outcomes (blastocyst formation rate and quality). Albeit not reaching statistical significance, the higher cumulative pregnancy rate in the study group seems clinically relevant.

Wider implications of the findings

Our results suggest that CCs can select more competent sperm for ICSI. This “physiologic-resembling”, operator-independent selection method has the potential of increasing pregnancy outcomes in ICSI cycles, pending of confirmation in larger studies including cumulative embryo-transfer cycles.

Trial registration number

NA

P-575 Follicle-stimulating hormone receptor genotype and its influence on the results of ovarian stimulation using corifollitropin alfa

Study question

Does the follicle-stimulating hormone receptor (FSHR) genotype influence the results of the ovarian stimulation treatment using corifollitropin alfa?

Summary answer

The use of collifolitropin alfa in SS genotype patients appears to be associated with the obtention of a lower number of oocytes and MII.

What is known already

Previous studies suggest that FSH receptor polymorphism in position 680 influences the response to ovarian stimulation: patients with SS genotype perform better with urinary FSH and need a higher dose of FSH to obtain similar results to the SN and NN genotypes.

These differences could be explained by the longer half-life of urinary gonadotropins, which might compensate for the lower affinity of the receptor in SS genotype patients. Our aim was to elucidate whether corifollitropin alfa, a long-acting recombinant FSH, has the same impact with respect to FSH receptor genotypes as recombinant FSH used habitually.

Study design, size, duration

One hundred and fifty-two egg donors were included in a retrospective cohort study between September 2019 and September 2020. In 80 of them, ovarian stimulation treatment was carried out using a single dose of Elonva 150 micrograms (Group 1). In 72 of them, in addition to the 150 microgram dose of Elonva, stimulation was continued with a daily dose of Puregon 225 UI from the eighth day of controlled ovarian stimulation (Group 2).

Participants/materials, setting, methods

To genotype the 680 position of the FSH receptor, a real-time PCR for allelic discrimination was carried out using StepOnePlus™ Real-Time PCR System (Applied Biosystems™). Linear regression analysis was performed to study the differences between the groups doing a correction for the variables anti-müllerian hormone, age and BMI. The statistical analysis was made with Software Statistical Product and Service Solutions, version 20.0 (SPSS, Chicago, IL, EE.UU.).

Main results and the role of chance

Regarding the whole set of patients, the results of ovarian stimulation using corifollitropin alfa are better in egg donors with SN and NN genotypes compared to those with SS genotype. Statistically significant differences were found in the number of retrieved oocytes (15.78 versus 10.83; p = 0.007) and retrieved MII (12.34 versus 9.00; p = 0.026).

There were no statistically significant differences between both groups of genotypes (SN-NN versus SS) in terms of age (24.04 versus 26.44; p = 0.514), BMI (22.22 versus 22.83; p = 0.781), anti-müllerian hormone levels (26.40 versus, 23.58; p = 0.495), antral follicle count (15.57 versus 14.97; p = 0.567) and the number of previous ovarian stimulations (2.71 versus 2.53; p = 0.812).

Studying both treatment groups separately, in Group 2, we find significant differences in the number of retrieved oocytes (17.55 versus 13.06, p = 0.012) and retrieved MII (14.25 versus 11.39; p = 0.031), between SN-NN versus SS, respectively.

On the other hand, in Group 1, we observe a trend towards statistical significance in the number of retrieved oocytes (13.83 versus 7.50, p = 0.089) and retrieved MII (10.24 versus 5.42; p = 0.120) comparing the same groups of genotypes.

Limitations, reasons for caution

The group of egg donors with the SS genotype barely represents 20% of the donors included in the study. This percentage is similar to its prevalence in the general population, so it is necessary to have a large sample size to be able to carry out studies regarding this genotype.

Wider implications of the findings

Despite the fact that corifollitropin alfa has a longer half-life, the results of SS patients do not match the rest of genotypes, so other factors must influence. Therefore, it would be advisable to genotype patients for 680 position of FSHR in order not to treat SS patients with this gonadotropin.

Trial registration number

-

O-063 Impact of group embryo culture vs individual embryo culture strategies on blastocyst rate and quality

Study question

Does group embryo culture improve blastocyst formation compared to individual culture?

Summary answer

Individual culture provides an increased blastocyst formation rate.

What is known already

Embryo culture is one of the most important steps of an IVF treatment. Several studies pointed out that group embryo culture could help embryos with lower potential, through paracrine signaling, to achieve development and improve blastocyst formation rate. On the other hand, this issue continues to be controversial and other studies did not find differences in embryo development when using either method.

Study design, size, duration

A prospective randomized study was performed between January 2020 and December 2021. The data were obtained from 830 embryos that came from 103 egg donation treatments. We defined two groups: individual vs group culture. The number of embryos analyzed in the study was calculated to test a difference of 10% in the rate of blastocyst formation between the two groups.

Participants/materials, setting, methods

A total of 103 ICSI-egg donation cycles with normozoospermic males (fresh samples) were included. After fertilization assessment, zygotes were randomized into two groups; Group 1: individual culture (399 embryos), and Group 2: culture of 2-5 embryos per drop (431 embryos). The embryos were cultured in 35 µl drops of Global Total medium until day 5 when they were classified morphologically according to Gardner criteria (1998). The statistical analysis was performed using SPSS (version 20.0).

Main results and the role of chance

The rate of high-quality embryos on day 3 were similar in Group 1 compared to Group 2 (79.2% vs 81.4%, p = 0.432). However, we observed an increase in the blastocyst formation rate on day 5 (62.9% vs 56.1%, p = 0.048) and a trend for higher embryo quality (A/B blastocysts) (55.9% vs 52%, p = 0.266) in Group 1; compared to Group 2, respectively.

Our data suggest that individual culture increases blastocyst formation rate and may benefit embryo quality on day 5. Our results challenge previous reports suggesting that culture in groups can improve embryo development. As hypothesis, we argue that some of the components that the embryos release to the culture environment during their division may affect the quality of the cohort potentially compromising further development up to the blastocyst stage.

Limitations, reasons for caution

The study is focused on laboratory outcomes until the blastocyst stage. Clinical outcomes were not analyzed.

Wider implications of the findings

Finding the most appropriate embryo culture conditions is essential to improve ART results. Time-lapse systems should be adapted to the use of both individual and group culture dishes. Larger randomized studies are needed in order to reach robust conclusions on the subject.

Trial registration number

NA

P-622 Clinical results in hormone replacement versus natural cycle protocols of endometrial preparation for frozen embryo transfer

Study question

What is the optimal endometrial preparation protocol for a frozen embryo transfer (FET) with regards to clinical results?

Summary answer

A similar pregnancy and miscarriage rate is expected with either protocol of endometrial preparation for frozen embryo transfer.

What is known already

An optimal endometrial preparation for FET is of paramount importance to maximize ART success. However, the optimal endometrial preparation protocol for FET warrants more research and is pending to be determined. In addition, in studies that reviewed the optimal endometrial preparation protocols, few of them analyzed the stage and the number of embryos or other factors such PGT-A.

Study design, size, duration

Multicenter, retrospective cohort evaluation of FET cycles in a private center (August 2020-March 2021). The type of endometrial preparation regime (hormone replacement vs natural cycle) was analyzed according to the following variables: origin of the oocyte (own / donated), single-embryo-transfer, PGT-A, day of embryo development and progesterone values on the day or the day before the embryo transfer procedure. The core outcome variables were pregnancy rate (positive β-hCG), clinical pregnancy and miscarriage rate.

Participants/materials, setting, methods

965 patients coming from autologous or heterologous cycles who performed FET. They were assigned to one group or another depending on the endometrial preparation regime used, either hormone replacement cycle (761) or natural cycle (204).

The normality of the distribution of the variables was assessed using the Shapiro-Wilk test. The statistical analysis was carried out by T-Student (quantitative variables) or Chi-squared test (qualitative variables).

Main results and the role of chance

Statistically significant differences were found between the use of donated oocyte on natural cycle (41.7%) and hormone replacement cycle (55.7%) (p = 0.001). Furthermore, day 5 embryo transfer differed significantly between natural cycle (78.4%) and hormone replacement cycle (86.3%) (p = 0.029), as well as day 6 embryo transfer between natural cycle (21.1%) and hormone replacement cycle (12.5%) (p = 0.029). Likewise, mean progesterone value on the day of the embryo transfer was significantly higher in natural cycle (24.4 ng/mL) than in hormone replacement cycle (18.55 ng/mL) (p = 0.00).

No statistically significant differences were found regarding pregnancy, clinical pregnancy and miscarriage rates between natural cycle (41.7, 31.9 and 23.1%) and hormone replacement cycle (44.7, 33.4 and 22.4%) (p = 0.48, 0.74 and 1.00), respectively. No significant differences were observed between the endometrial preparation regime regarding single-embryo-transfer and PGT-A (p > 0.05).

Limitations, reasons for caution

The inherent limitations of a retrospective study. Different routes of administration and doses of hormones were employed in the hormone replacement cycle. Similarly, natural cycles included: “true” and modified (hCG-triggered) cycles. Obstetric / perinatal outcomes were not evaluated.

Wider implications of the findings

Our results suggest no particular benefit of one protocol over the other in terms of clinical results. Nonetheless, the higher progesterone values detected in natural cycles might be clinically relevant in view of the positive correlation between P4 levels on the day of frozen-thawed embryo transfer (FET) with pregnancy outcomes.

Trial registration number

Not Applicable

P–158 Assisted Hatching on D + 3 in order to facilitate trophectoderm biopsy in blastocyst for PGT-A is not advisable in all patients

Study question

Is it useful or beneficial to perform Assisted Hatching (AH) on D + 3 previously to biopsy for PGT-A on blastocyst stage on D + 5?

Summary answer

The routine use of AH on D + 3 to facilitate the embryo biopsy on D + 5 could negatively influence the development of the embryos to blastocyst stage.

What is known already

The blastocyst stage is the optimal stage for performing biopsies for PGT-A, which has been reported as a key factor determining the growing clinical application of this strategy worldwide. For trophectoderm (TE) biopsy, laser-assisted drilling is used to create a zona opening on D + 3 or D + 5 of development. The method of zona opening on D + 3 allows some of the TE cells to herniate during blastocyst formation and expansion, which facilitates the biopsy process. However, this method may result in herniation of inner cell mass cells instead of TE or maybe could affect the development of the embryo to blastocyst stage.

Study design, size, duration

A total of 100 PGT-A cycles were performed in 2019 and 2020. In 78 of them laser-assisted drilling was used to create a zona opening on D + 5 only in those embryos which arrived to blastocyst stage for TE biopsy (Group No-AH). In 22 cycles the same drilling was achieved on D + 3 in all embryos, independently of their quality (Group AH). The average of embryos per cycle in each group was 5 and 4.3 respectively.

Participants/materials, setting, methods

A total of 100 PGT-A cycles coming from 65 patients were studied. The average of the age of the patients was 40.83 (SD 3.45) in the group No-AH vs 42.18 (SD 3.42) in the Group AH (p = 0.108), so the age was not a determining factor for the development of the embryos. We analyzed by χ 2 test differences between groups on fertilization rates, number of embryos, development to blastocyst stage, euploidy and pregnancy rates.

Main results and the role of chance

The fertilization rate was 74.79% (No-AH group) and 68.53% (AH group) with no significative statistical differences (p = 0.12).

In the No-AH group, the TE biopsy was performed on D + 5 in 63 cycles (81%). In the AH group, 41% of cycles didn’t reach the blastocyst stage, obtaining statistical differences between groups (p = 0.035). We found also significant differences in the number of cycles with biopsied blastocyst when we had 1 to 6 embryos/cycle on D + 3 between groups (p = 0.002), without obtaining any blastocyst to be diagnosed in 53% of the cycles in AH group vs 27% in No-AH group. When the number of embryos on D + 3 per cycle was > 6, at least 1 embryo reached the blastocyst stage in both groups, although this number was higher in No-AH group. The rate of biopsied blastocysts was significantly higher in the No-AH group compared to the AH group (46.61 vs 34.69) with a p = 0.031.

The rate of euploid embryos analyzed was 23.30% in the No-AH group compared to 29.41% in the AH group, although no significant differences were found (p = 0.44) between groups.

In the No-AH group, a clinical pregnancy rate of 52.94% was obtained (n = 34) vs 50% in the AH group (n = 4) (p = 0.91).

Limitations, reasons for caution

We have recently started to perform AH on D + 3, so the number of cases is smaller than No-AH group. We use a time lapse incubator in all cases, so in the No-AH the culture dish is changed, disturbing the stable incubation environment, while in the other group it is not.

Wider implications of the findings: The use of AH on D + 3 in order to facilitate the TE biopsy on D + 5 could affect negatively the development of the embryos to blastocyst stage. Its routine use should be avoided based on laboratory workload, mainly if the patient has less than 7 embryos at D + 3.

Trial registration number

Not applicable

P–162 Laser-assisted collapse of blastocysts prior to vitrification improves clinical outcomes

Study question

What is the effect of artificial laser-assisted collapse before vitrification on pregnancy and implantation rates after transfer of vitrified-warmed blastocysts?

Summary answer

The artificial shrinkage by laser-induced collapse before vitrification significantly increased the implantation and clinical pregnancy rates after single thawed embryo transfer.

What is known already

Freeze all, cycle segmentation and, in general, single embryo transfer (SET) strategies (for example trophectoderm biopsy-based aneuploidy testing) have targeted blastocysts vitrification as the best option for reproductive practice worldwide. Artificial shrinkage seems to be a pre-vitrification parameter associated with an increased embryo survival after warming and implantation rate. However, the available medical evidence shows controversial results with only a limited number of prospective studies assessing the subject.

Study design, size, duration

This prospective cohort study evaluated 394 women who underwent a frozen blastocyst transfer at Instituto Bernabeu between July and December 2020. All patients were prepared with substitutive cycle and received single blastocyst embryo transfers.

Participants/materials, setting, methods

Before embryo vitrification on day 5 of development, some expanded and/or early hatching blastocysts (A/B ASEBIR categories) were artificial laser-assisted collapsed. (n = 83, study group). 311 embryos of the same quality and day of development were not collapsed (control group). We compared the embryo survival rate, clinical, implantation and miscarriage rates between groups. The statistical analysis was performed using SPSS (version 20.0).

Main results and the role of chance

The two groups were comparable in terms of maternal age (39.79 ± 3.83, control group; 40.21 ± 4.45, study group; p = 0.341). Embryo survival rate resulted in 100% in both groups.

Regarding clinical outcomes, collapsed blastocysts significantly increased the positive pregnancy test and the clinical pregnancy and implantation rate compared to the control group, respectively (positive test: 69,9% vs 43,4%, p = 0.000018, odds ratio (OR)= 3.02 [95% CI 1.80–5.08]; clinical pregnancy and implantation: 56,6% vs 35,4%, p = 0.000041, OR = 2.39 [95% CI 1.46–3.90]). The miscarriage rate was not affected by the blastocyst collapse effect (23,6% in the control group vs 27,6% in the study group, p = 0.593, OR = 1.23 [95% CI 0.57–2.68]).

Limitations, reasons for caution

This is a non-randomized controlled study. Additional RCTs are warranted to corroborate our findings.

Wider implications of the findings: Considering the large number of blastocyst vitrification cycles that are carried out worldwide, artificial laser-assisted collapse before vitrification has the potential to increase the clinical results in benefit of many patients.

Trial registration number

Not applicable

P–550 Clinical outcomes of mosaic embryos are similar between young and older women

Study question

Are there differences in the clinical outcomes of mosaic embryos depending on the female age?

Summary answer

Clinical outcomes of mosaic embryo transfers are similar regardless female age.

What is known already

Chromosomal abnormalities are common in embryos analyzed in preimplantation genetic testing for aneuploidy (PGT-A) cycles. Mosaicism (the presence of two or more chromosomally distinct cell lines) is a usual event in embryos derived from IVF cycles.

Several studies show that mosaic embryos have reduced potential to reach term, compared to euploid embryos. The factors affecting the implantation potential and development of mosaic embryos are controversial. Recently, Victor et al. (2019) argued that mosaic blastocysts generated at younger ages show better outcomes compared to older ages. The aim of this study was to test this hypothesis in our centre.

Study design, size, duration

A total of 136 mosaic embryos from patients undergoing PGT-A cycles from May 2014 to October 2020 were retrospectively analyzed in this study. The blastocyst trophoectoderm biopsies of day 5 and 6 were analysed by aCGH (n = 47, 30.1%) and NGS (n = 109, 69.9%). An embryo was considered mosaic when the percentage of aneuploid cells were 25–50% in aCGH and 20–50% in NGS. Only single embryo transfer cycles were included in the analysis.

Participants/materials, setting, methods

Embryo analysis were performed using Agilent SurePrint G3 8x60K CGH microarrays or Veriseq NGS (Illumina), with previous whole genome amplification. We evaluated if clinical results of mosaic embryos transfers in IVF cycles were correlated with female age. The main outcome measures were β-hCG, implantation rate and ongoing pregnancy rate. β-hCG was measured in blood 14 days after the embryo transfer and was considered positive when it was >2 mUI/ml.The statistical analysis was performed with SPSSv20.0.

Main results and the role of chance

A total of 136 mosaic embryos were included in this study. Overall, we evaluated factors affecting embryo mosaicism implantation potential. Neither the percentage of mosaicism nor the segmental mosaicism were related to mosaic embryo implantation, pregnancy and ongoing pregnancy rates.

To evaluate the impact of female age in clinical outcomes, we established two different groups depending on whether mosaic blastocysts were generated from oocytes retrieved at young maternal ages (≤35 years; n = 62) or at older ages (>35years; n = 74).

No differences were found between groups. Nonetheless, to reduce bias, embryo quality, percentage of mosaicism, segmental mosaicism and whether the transferred embryo was frozen or fresh were included as confounding factors.

The rate of positive β-hCG was similar between groups: 45.2% in ≤ 35y group vs 54.1% in > 35y (p = 0.476). The implantation rate was also similar: 30.6% vs 39.2%% (p = 0.855), respectively. Furthermore, the ongoing pregnancy rate was higher in the >35y group (35.1%), compared to the ≤35y group (19.4%) without reaching statistically significant differences (p = 0.245).

Limitations, reasons for caution

The sample size is a limitation. aCGH test and a different definition for mosaic embryo in terms of percentage of abnormal cells was employed in this study compared to Victor et. al. (2019) study. Larger prospective studies should evaluate the impact of maternal age in the outcome of mosaic embryos.

Wider implications of the findings: Our results challenge that female age is associated with clinical outcomes after the transfer of mosaic embryos. Comparable results were obtained in young and older women. Therefore, in the absence of euploid embryos, mosaic embryos might be considered for transfer and similar outcomes are expected regardless of the maternal age.

Trial registration number

Not applicable

P–701 Fresh vs frozen PGT-A cycles in donor oocyte recipients

Study question

For donor oocyte recipients, are clinical outcomes superior for fresh versus frozen euploid embryos?

Summary answer

Among donor oocyte recipients receiving euploid embryos, fresh embryos are associated with superior clinical outcomes when compared with frozen embryos.

What is known already

A recent large retrospective cohort national registry study reported that among donor oocyte recipients, fresh embryos were associated with better clinical outcomes when compared with frozen embryos. This finding contrast with data from autologous oocytes. Since embryo quality at embryo transfer (ET) may introduce a significant confounder, the additional analysis of recipients receiving only euploid embryos may add important information on the subject.

Study design, size, duration

Retrospective cohort analysis of PGT-A IVF-cycles of women using donor oocytes resulting in fresh blastocyst ET compared to the first frozen blastocyst ET from freeze-all cycles between 2014 and 2020 at Instituto Bernabeu, Alicante, Spain. A total of 349 donor oocyte cycles were analyzed, in which 211 were fresh and 138 were frozen ETs. Thawed oocytes were not excluded.

Participants/materials, setting, methods

Clinical pregnancy (gestational sac plus embryo heart beating at 6–7 weeks), was the primary outcome measure. Secondary outcomes included pregnancy and early pregnancy loss rate. aCGH platform tested the embryos transferred in fresh whereas either aCGH or NGS platforms were used for embryos submitted to elective frozen cycles. Vitrification was used as cryopreservation technique. Fresh transfers were performed in artificial cycles. Different types of endometrial preparations were used for FET in the study.

Main results and the role of chance

Recipients in the fresh group were significantly younger and had more embryos transferred compared to the frozen group (41.3 vs 42.5 and 1.2 vs 1.1, respectively). More clinical pregnancies were observed in the fresh compared to the frozen group (108/211 versus 54/138, respectively, odds ratio (ODR) 1.63 [95% CI 1.05–2.52]; p = 0.02). Pregnancy rates were also higher in the fresh compared to the frozen group (128/211 versus 63/138, respectively, odds ratio (ODR) 1.83 [95% CI 1.18–2.83]; p = 0.005). Early pregnancy losses were similar in both groups (p = 0.2).

Limitations, reasons for caution

Implantation failure and abnormal male tests were the most frequent indications for PGT-A. Because of the observational nature of the results in this limited sample size, a cause–effect relationship should not be assumed; evidence from larger well-designed randomized control trials is still required before clinical advice can be suggested.

Wider implications of the findings: When PGT-A analysis is deemed to be necessary in oocyte recipients, cryopreservation may have an adverse impact on IVF outcomes. Future studies exploring ET in natural vs artificial cycles are warranted to further isolate the impact of vitrification and the uterine environment on IVF outcomes.

Trial registration number

Not applicable

The nucleus pulposus microenvironment in the intervertebral disc: the fountain of youth?

The intervertebral disc (IVD) is a complex tissue, and its degeneration remains a problem for patients, without significant improvement in treatment strategies. This mostly age-related disease predominantly affects the nucleus pulposus (NP), the central region of the IVD. The NP tissue, and especially its microenvironment, exhibit changes that may be involved at the outset or affect the progression of IVD pathology. The NP tissue microenvironment is unique and can be defined by a variety of specific factors and components characteristic of its physiology and function. NP progenitor cell interactions with their surrounding microenvironment may be a key factor for the regulation of cellular metabolism, phenotype, and stemness. Recently, celltransplantation approaches have been investigated for the treatment of degenerative disc disease, highlighting the need to better understand if and how transplanted cells can give rise to healthy NP tissue. Hence, understanding all the components of the NP microenvironment seems to be critical to better gauge the success and outcomes of approaches for tissue engineering and future clinical applications. Knowledge about the components of the NP microenvironment, how NP progenitor cells interact with them, and how changes in their surroundings can alter their function is summarised. Recent discoveries in NP tissue engineering linked to the microenvironment are also reviewed, meaning how crosstalk within the microenvironment can be adjusted to promote NP regeneration. Associated clinical problems are also considered, connecting bench-to-bedside in the context of IVD degeneration.

Managing the pandemic from the radiology department's point of view

The COVID-19 pandemic is forcing our entire society to adopt numerous changes, at least until an effective treatment and/or vaccine becomes widely available. Because COVID-19 is a new disease that has required us to make complex decisions based on scant evidence, the pandemic is having an enormous impact on our health system. Radiology departments play a fundamental role in the management of COVID-19, both in the diagnosis of the disease and in the posterior management of patients. To ensure the safety of patients and healthcare professionals, it is essential to understand the infection so that safe circuits can be implemented. This article summarizes the pathophysiology of COVID-19 infection and explains the measures that radiology departments need to adopt during the pandemic.

SAT0004 INCREASED M1 INFLAMMATORY PHENOTYPE OF CIRCULATING MONOCYTES IS ASSOCIATED WITH HISTORY OF CARDIOVASCULAR EVENTS IN RA PATIENTS

Background:

Cardiovascular (CV) Disease is the main cause of death in Rheumatoid Arthritis (RA). Current tools like Framingham or European SCORE underestimate CV risk in RA patients. Efforts to improve the assessment including RA biomarkers (disease activity) have been only partially successful. There is a need for better biomarkers to identify AR patients at high risk for CV disease. Monocytes have an important role in plaque development. Monocytes differentiates into 2 main phenotypes M1 and M2 (1). In RA and in post-MI patients M1 monocytes are expanded (2). mTORC influences monocyte phenotypein vitroand has been associated with development of atheromatous plaque (3).

Objectives:

To evaluate the phenotype of circulating monocyte in RA patient with or without previous CV events (RA-CV(-)RA-CV(+)), and its possible association with mTORC activity.

Methods:

9 RA-CV(+)patients aged between 18 and 65 yo with RA (EULAR/ACR 2010 criteria), were paired with RA-CV(-)patients. 6 healthy individuals (HI) were also studied. Pairing criteria were classic CV risk factors (AHA 2018), sex, age, years since RA diagnosis, comorbidities, number of DMARDs previously used and use of bDMARDS. M1 and M2 circulating Monocytes were evaluated in PBMC obtained from patients and controls by flow cytometry analysis. Intracellular inflammatory cytokines (IL1, Il6) and phosphorylated S6R (P-S6R) as a measure of mTORC activation was also evaluated. M1 was defined as CD14+HLA-DR+CCR2+ and M2 CD14+CD163+CCR2-. DAS28-RCP, DAS28-ESR and Lipid profile was also measured. The differences among groups was analysed using Mann–Whitney U nonparametric. The relationship between variables with Spearman rank correlation test.

Results:

There were no differences in demographic, RA characteristic and CV risk factors between RA-CV (+) and RA-CV (-) patients. Male/Female 4/5, age 62±3 and 63±2 respectively. HI were younger than RA patients (32.5±7). CV events were 8 patients with MI and one Stroke. DAS28-RCP was 2.96±0.23 and 2.88±0.43 respectively. One patient in each group had failed to more than 2 sDMARDs and one in each group was receiving bDMARD. M1 circulating monocytes were expanded in RA as compared to HI. This difference was at RA-CV (+) expense. RA monocytes had higher Intracellular levels of IL-1b and IL-6 as compared to HI. M1 from RA-CV (+) had higher intracellular levels of IL-1b and IL-6 than RA-CV (-). M1 monocytes have higher levels of inflammatory cytokines than M2. P-S6R protein, (mTORC activation), was higher in RA patients than HI. The highest levels of P-S6R was observed in M1 monocytes from RA-CV(+) population.

FIGURE 1.

Circulating monocytes phenotype, intracellular cytokines and phosphorylated S6R in HI and RA-CV (+), RA-CV (-) and the combined RA patients. A) *=0,02; B) *=0,016; C) ****=0,0001, **=0,002; D) ****=0,0001, ***=0,0008, **=0,001, *=0,01; E) ****0,0001, **=0,002; F) ****=0,0001, **=0,001, **=0,003.

Conclusion:

RA-CV+ patients, have a significantly higher number of pro-inflammatory circulating monocytes, using a multiparametric classification method. These monocytes also express higher levels of inflammatory cytokines and higher activation of mTORC, which also participate in the development of atheromatous plaque, suggesting that these monocytes could be a key element in the non-clarified-yet, excess of CV risk of RA patients.

References:

[1] Fukui S, et al. M1 and M2 Monocytes in Rheumatoid Arthritis: A Contribution of Imbalance of M1/M2 Monocytes to Osteoclastogenesis. Front Immunol. 2017;8:1958.2. Zhuang J, et al. Comparison of circulating dendritic cell and monocyte subsets at different stages of atherosclerosis: insights from optical coherence tomography. BMC Cardiovasc Disord. 2017 Oct 18;17(1):270.

Disclosure of Interests:

None declared

Coumarin Derivative Directly Coordinated to Lanthanides Acts as an Excellent Antenna for UV-Vis and Near-IR Emission

A chelating coumarin-derived ligand sensitizes all emitting lanthanide ions in the solid state and gives high absolute quantum yields for ethanol solutions of complexes of Sm, Eu, Tb, and Dy, above 20% for the last two. Crystal structures of these four complexes are [Ln(Cum)₃(H₂O)(X)]·X where X = MeOH or EtOH.

Anti-inflammatory effect as a mechanism of effectiveness underlying the clinical benefits of pelotherapy in osteoarthritis patients: regulation of the altered inflammatory and stress feedback response

The purpose of the present investigation was to evaluate whether an anti-inflammatory effect together with an improvement of the regulation of the interaction between the inflammatory and stress responses underlies the clinical benefits of pelotherapy in osteoarthritis (OA) patients. This study evaluated the effects of a 10-day cycle of pelotherapy at the spa centre 'El Raposo' (Spain) in a group of 21 OA patients diagnosed with primary knee OA. Clinical assessments included pain intensity using a visual analog scale; pain, stiffness and physical function using the Western Ontario and McMaster Universities Arthritis Index; and health-related quality of life using the EuroQol-5D questionnaire. Serum inflammatory cytokine levels (IL-1β, TNF-α, IL-8, IL-6, IL-10 and TGF-β) were evaluated using the Bio-Plex® Luminex® system. Circulating neuroendocrine-stress biomarkers, such as cortisol and extracellular 72 kDa heat shock protein (eHsp72), were measured by ELISA. After the cycle of mud therapy, OA patients improved the knee flexion angle and OA-related pain, stiffness and physical function, and they reported a better health-related quality of life. Serum concentrations of IL-1β, TNF-α, IL-8, IL-6 and TGF-β, as well as eHsp72, were markedly decreased. Besides, systemic levels of cortisol increased significantly. These results confirm that the clinical benefits of mud therapy may well be mediated, at least in part, by its systemic anti-inflammatory effects and neuroendocrine-immune regulation in OA patients. Thus, mud therapy could be an effective alternative treatment in the management of OA.

Spatial modes in one-dimensional models for capillary jets

One-dimensional (1D) models are widely employed to simplify the analysis of axisymmetric capillary jets. These models postulate that, for slender deformations of the free surface, the radial profile of the axial velocity can be approximated as uniform (viscous slice, averaged, and Cosserat models) or parabolic (parabolic model). In classical works on spatial stability analysis with 1D models, considerable misinterpretation was generated about the modes yielded by each model. The already existing physical analysis of three-dimensional (3D) axisymmetric spatial modes enables us to relate these 1D spatial modes to the exact 3D counterparts. To do so, we address the surface stimulation problem, which can be treated as linear, by considering the effect of normal and tangential stresses to perturb the jet. A Green's function for a spatially local stimulation having a harmonic time dependence provides the general formalism to describe any time-periodic stimulation. The Green's function of this signaling problem is known to be a superposition of the spatial modes, but in fact these modes are of fundamental nature, i.e., not restricted to the surface stimulation problem. The smallness of the wave number associated with each mode is the criterion to validate or invalidate the 1D approaches. The proposed axial-velocity profiles (planar or parabolic) also have a remarkable influence on the outcomes of each 1D model. We also compare with the classical 3D results for (i) conditions for absolute instability, and (ii) the amplitude of the unstable mode resulting from both normal and tangential surface stress stimulation. Incidentally, as a previous task, we need to re-deduce 1D models in order to include eventual stresses of various possible origins (electrohydrodynamic, thermocapillary, etc.) applied on the free surface, which were not considered in the previous general formulations.

Optical finite representation of the Lorentz group

We implement a finite-dimensional representation of the 2+1D Lorentz group with a PT-symmetric waveguide array. Our device can be engineered to behave like a multi-port oscillator or directional coupler with amplification. We show that the two-waveguide coupler with linear losses, the Vernier effect in coupled asymmetric micro-cavity lasers, and the so-called linear PT-symmetric dimer belong to this symmetry class of optical systems.

Effects of doxycycline on heartworm embryogenesis, transmission, circulating microfilaria, and adult worms in microfilaremic dogs

Tetracycline treatment of animals or humans infected with filariae that harbor Wolbachia endosymbionts blocks further embryogenesis, and existing microfilariae gradually die. This treatment also kills developing larvae and has a slow-kill effect on adult filariae, all presumably due to elimination of the Wolbachia. Also, Dirofilaria immitis microfilariae in blood collected from dogs up to 25 days after the last dose of doxycycline developed to infective L3 that were normal in appearance and motility in mosquitoes but did not continue to develop or migrate normally after subcutaneous (SC) injection into dogs. The present study was designed to determine whether heartworm microfilariae collected at later times after treatment would regain the ability to continue normal development in a dog. The study also was expected to yield valuable data on the effects of treatment on microfilariae and antigen levels and adult worms. The study was conducted in 16 dogs as two separate replicates at different times. A total of five dogs (two in Replicate A and three in Replicate B) infected either by SC injection of L3 or intravenous transplantation of adult heartworms were given doxycycline orally at 10mg/kg twice daily for 30 days, with three untreated controls. Microfilarial counts in the five treated dogs gradually declined during the 12-13 months after treatment initiation. Two dogs were amicrofilaremic before necropsy and three had 13 or fewer microfilariae/ml. Only one treated dog was negative for heartworm antigen before necropsy. Overall, treated dogs generally had fewer live adult heartworms than controls, and most of their live worms were moribund. All three control dogs remained positive for microfilariae and antigen and had many live worms. L3 from mosquitoes fed on blood collected 73-77 or 161-164 days after initiation of doxycycline treatments were injected SC into five dogs. None of the dogs injected with L3 from mosquitoes fed on blood from doxycycline-treated dogs were ever positive for microfilariae or antigen, and none had worms at necropsy; three control dogs were positive for microfilariae and antigen and had many live worms. These data indicate that doxycycline treatment of microfilaremic dogs gradually reduces numbers of microfilariae and blocks further transmission of heartworms. This latter effect should be highly effective in reducing the rate of selection of heartworms with genes that confer resistance to macrocyclic lactone preventives and microfilaricides. The data also suggest that doxycycline has a slow-kill effect on adult heartworms.

First Report of Diaporthe australafricana-Caused Stem Canker and Dieback in European Hazelnut (Corylus avellana L.) in Chile

European hazelnut (Corylus avellana L.) is an emerging crop for export, mainly in southern Chile. Stem cankers and dieback of twigs on six-year-old European hazelnut cultivar Barcelona were observed during the 2012 growing season on plantations in Panguipulli (39° 38' 37.12″ S and 72° 20' 10.87″ W), Region de Los Rios, Chile. The incidence has been variable according to the place of plantation; it was estimated at approximately 15%. Cankers were characterized by brownish-gray and brown to reddish discoloration of the vascular stem system. Hazelnut plants between 1 and 3 years old developed stem basal canker, especially at conditions of high humidity and overpopulation of weeds; at critical conditions, the affected plants generally die. Small pieces of cankered stems, selected from 10 European hazelnuts, were surface sterilized in 0.5% sodium hypochlorite for 2 min and rinsed twice in sterile distilled water prior to incubation in a humid chamber for 7 days (25 ± 2°C) to stimulate production of reproductive bodies. Black sub-epidermal perithecia with unitunicate, cylindrical-clavate, 8-spored asci (n = 20) were obtained. Ascospores were septated, hyaline, multigutulate, and slightly constricted at the septum, the average measurements were (n = 20) 13.4 ± 0.6 μm × 3.9 ± 0.2 μm. The ascospores were transferred to potato dextrose agar (PDA) and incubated for 6 days at 25°C in the dark, then hyphal tips were transferred to fresh PDA and obtained a mycelia with white, cottony, and sparse colonies. Pycnidia and smooth, unicellular, hyaline, and biguttulate alpha conidia of 6.1 to 7.2 μm × 2.8 to 3.1 μm (n = 40) were observed. Beta conidia were not observed in culture media. Mature pycnidia were also detected on hazelnut shells remaining on the soil from the previous season. The identification of the species (isolate IMI-501237) was confirmed at CABI, United Kingdom, using an internal transcribed spacer (ITS), rDNA, BLASTn analysis of the 524-bp fragment, and showed 100% identity with Diaporthe australafricana Crous & J.M. van Niekerk (accessions KC343039, KC343038). These molecular and morphological characteristics were similar that reported from Vitis vinifera (2) and Chilean blueberry (3). The sequence obtained was deposited in GenBank (Accession No. JX316218.1). A pathogenicity test was conducted with isolate IMI-501237 on four 1-year-old plants from the hazelnut cultivar Barcelona. Plants were maintained in individual bags in greenhouse conditions (14/10 h dark/light, 20°C; 70% relative humidity). Prior to inoculation, plant tissues were surface disinfected with 2% sodium hypochlorite and rinsed with sterile distilled water. Each plant was inoculated at fresh wound sites on three stems and three vegetative buds on twigs. The inoculum consisted of an agar plug with mycelia (5 mm) from the edge of an actively growing colony cultured on PDA for 6 days. Each inoculation was covered with moistened cotton and sealed with Parafilm; a control plant was inoculated in the same way with agar only. After 30 days, necrotic lesions and discolored vascular tissue were only observed on inoculated stems and twigs. Symptomatic tissues were removed and incubated on PDA. D. australafricana was consistently recovered from these tissues, satisfying Koch's postulates. The control plant showed no symptoms of the disease. D. australafricana were previously reported on Vitis vinifera in Australia and South Africa (2,4), and Vaccinium corymbosum in Chile (1,3). To our knowledge, this is the first report of Diaporthe australafricana on Corylus avellana cultivar Barcelona in worldwide. References: (1) K. Elfar et al. Plant Dis. 97:1042, 2013. (2) R. Gomes et al. Persoonia 31:1, 2013. (3) B. Latorre et al. Plant Dis. 96:5, 2012. (4) J. M. van Niekerk et al. Australas. Plant Pathol. 34:27, 2005.

Cell interactions between human progenitor-derived endothelial cells and human mesenchymal stem cells in a three-dimensional macroporous polysaccharide-based scaffold promote osteogenesis

Several studies have reported the benefits of mesenchymal stem cells (MSCs) for bone tissue engineering. However, vascularization remains one of the main obstacles that must be overcome to reconstruct large bone defects. In vitro prevascularization of the three-dimensional (3-D) constructs using co-cultures of human progenitor-derived endothelial cells (PDECs) with human bone marrow mesenchymal stem cells (HBMSCs) appeared as a potential strategy. However, the crosstalk between the two lineages has been studied in two-dimensional (2-D), but remains unknown in 3-D. The aim of this study is to investigate the cell interactions between PDECs and HBMSCs in a porous matrix composed of polysaccharides. This biodegradable scaffold promotes cell interactions by inducing multicellular aggregates composed of HBMSCs surrounded by PDECs. Cell aggregation contributes to the formation of junctional proteins composed of Connexin43 (Cx43) and VE-cadherin, and an activation of osteoblastic differentiation of HBMSCs stimulated by the presence of PDECs. Inhibition of Cx43 by mimetic peptide 43GAP27 induced a decrease in mRNA levels of Cx43 and all the bone-specific markers. Finally, subcutaneous implantations for 3 and 8 weeks in NOG mice revealed an increase in osteoid formation with the tissue-engineered constructs seeded with HBMSCs/PDECs compared with those loaded with HBMSCs alone. Taking together, these results demonstrate that this 3-D microenvironment favored cell communication, osteogenesis and bone formation.