Spatially Self-Organized Three-Dimensional Neural Concentroid as a Novel Reductionist Humanized Model to Study Neurovascular Development

Although human pluripotent stem cell (PSC)-derived brain organoids have enabled researchers to gain insight into human brain development and disease, these organoids contain solely ectodermal cells and are not vascularized as occurs during brain development. Here it is created less complex and more homogenous large neural constructs starting from PSC-derived neuroprogenitor cells (NPC), by fusing small NPC spheroids into so-called concentroids. Such concentroids consisted of a pro-angiogenic core, containing neuronal and outer radial glia cells, surrounded by an astroglia-dense outer layer. Incorporating PSC-derived endothelial cells (EC) around and/or in the concentroids promoted vascularization, accompanied by differential outgrowth and differentiation of neuronal and astroglia cells, as well as the development of ectodermal-derived pericyte-like mural cells co-localizing with EC networks. Single nucleus transcriptomic analysis revealed an enhanced neural cell subtype maturation and diversity in EC-containing concentroids, which better resemble the fetal human brain compared to classical organoids or NPC-only concentroids. This PSC-derived "vascularized" concentroid brain model will facilitate the study of neurovascular/blood-brain barrier development, neural cell migration, and the development of effective in vitro vascularization strategies of brain mimics.

Disruption of MAM integrity in mutant FUS oligodendroglial progenitors from hiPSCs

Amyotrophic lateral sclerosis (ALS) is a rapidly progressive and fatal neurodegenerative disorder, characterized by selective loss of motor neurons (MNs). A number of causative genetic mutations underlie the disease, including mutations in the fused in sarcoma (FUS) gene, which can lead to both juvenile and late-onset ALS. Although ALS results from MN death, there is evidence that dysfunctional glial cells, including oligodendroglia, contribute to neurodegeneration. Here, we used human induced pluripotent stem cells (hiPSCs) with a R521H or a P525L mutation in FUS and their isogenic controls to generate oligodendrocyte progenitor cells (OPCs) by inducing SOX10 expression from a TET-On SOX10 cassette. Mutant and control iPSCs differentiated efficiently into OPCs. RNA sequencing identified a myelin sheath-related phenotype in mutant OPCs. Lipidomic studies demonstrated defects in myelin-related lipids, with a reduction of glycerophospholipids in mutant OPCs. Interestingly, FUSR521H OPCs displayed a decrease in the phosphatidylcholine/phosphatidylethanolamine ratio, known to be associated with maintaining membrane integrity. A proximity ligation assay further indicated that mitochondria-associated endoplasmic reticulum membranes (MAM) were diminished in both mutant FUS OPCs. Moreover, both mutant FUS OPCs displayed increased susceptibility to ER stress when exposed to thapsigargin, and exhibited impaired mitochondrial respiration and reduced Ca2+ signaling from ER Ca2+ stores. Taken together, these results demonstrate a pathological role of mutant FUS in OPCs, causing defects in lipid metabolism associated with MAM disruption manifested by impaired mitochondrial metabolism with increased susceptibility to ER stress and with suppressed physiological Ca2+ signaling. As such, further exploration of the role of oligodendrocyte dysfunction in the demise of MNs is crucial and will provide new insights into the complex cellular mechanisms underlying ALS.

CRISPR/Cas9 screen in human iPSC-derived cortical neurons identifies NEK6 as a novel disease modifier of C9orf72 poly(PR) toxicity

INTRODUCTION

The most common genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are hexanucleotide repeats in chromosome 9 open reading frame 72 (C9orf72). These repeats produce dipeptide repeat proteins with poly(PR) being the most toxic one.

METHODS

We performed a kinome-wide CRISPR/Cas9 knock-out screen in human induced pluripotent stem cell (iPSC) -derived cortical neurons to identify modifiers of poly(PR) toxicity, and validated the role of candidate modifiers using in vitro, in vivo, and ex-vivo studies.

RESULTS

Knock-down of NIMA-related kinase 6 (NEK6) prevented neuronal toxicity caused by poly(PR). Knock-down of nek6 also ameliorated the poly(PR)-induced axonopathy in zebrafish and NEK6 was aberrantly expressed in C9orf72 patients. Suppression of NEK6 expression and NEK6 activity inhibition rescued axonal transport defects in cortical neurons from C9orf72 patient iPSCs, at least partially by reversing p53-related DNA damage.

DISCUSSION

We identified NEK6, which regulates poly(PR)-mediated p53-related DNA damage, as a novel therapeutic target for C9orf72 FTD/ALS.

P-335 How to define recurrent implantation failure and when to start investigating the endometrium? Lessons from three years’ experience in a dedicated unit

Study question

Should we always define recurrent implantation failure (RIF) after three unsuccessful transfers and only then start investigating the endometrium?

Summary answer

Endometrial investigations can be beneficial for patients with RIF. However, waiting for three previous failures before instituting assessment might not be appropriate in every situation.

What is known already

The definition of unexplained recurrent implantation failure (RIF) continues to be debated. This usually implies a lack of embryo implantation after the transfer of three good quality blastocysts on an apparently responsive and anatomically normal endometrium. To deal with this frustrating and distressing situation for both the patient and the clinician, additional empirical interventions are often blindly used. This approach may exacerbate rather than ameliorate any underlying aetiology. There is a need therefore to base interventions on diagnostic rationale wherever possible.

Study design, size, duration

In order to base advice and any interventions for RIF on diagnostic rationale, we created a referral unit dedicated to the investigation and treatment of patients meeting the traditional criteria for RIF. Over three years, 395 patients were referred to this unit and 237 completed their investigations. Here we present the clinical outcomes and insights obtained over these three years.

Participants/materials, setting, methods

Blood sampling for serum progesterone level and endometrial pipelle biopsy were performed after five days of luteal support in a standardised substituted cycle. The samples underwent dating by gene expression (ERA test) and immune assessment describing the recruitment and activation of the uterine Natural Killer cells (MLI test, Matrice Lab Innove). A personalised treatment plan was thus derived and suggested to the referring clinician. The outcomes after the subsequent personalised single embryo transfer were monitored.

Main results and the role of chance

The patients referred had an average of 4.3 previous good quality blastocysts transferred in the past. 58% of the referred patients had used their own eggs, including 49% after conventional IVF or ICSI, and 9% after using PGT-A. 42% of the referred patients had used donor eggs. To date, 237 patients completed their endometrial assessment. 92% of the tested patients revealed at least one disrupted endometrial marker. With the subsequent personalised single embryo transfer, an implantation rate of 58% was observed. The ongoing pregnancy rate at 12 weeks was reported at 39%.

Limitations, reasons for caution

While confirmatory prospective controlled studies are required, these data indicate that more targeted rather than blind usage of simple known therapeutics could be beneficial for patients experiencing RIF. The clinical context these referred was highly variable, including patients undergoing PGT-A and egg donation.

Wider implications of the findings

Given the higher implantation rates to be expected in some groups, waiting for at least three embryos to fail before investigating the endometrium may be inappropriate and underlie the relatively high miscarriage rate observed. The investigation of implantation failure should be driven by context rather than arbitrary definition.

Trial registration number

Not Applicable

P-191 Differences in morphokinetic patterns and clinical outcomes between fresh and frozen oocytes; a retrospective analysis

Study question

Is there a difference in morphokinetics and clinical outcomes between embryos from fresh and vitrified oocytes?

Summary answer

Embryos from vitrified versus fresh oocytes showed a delay at the cellular stage, but no impact on time to blastulation or clinical outcomes was evident.

What is known already

Oocyte vitrification has greatly impacted assisted reproduction, with the number of treatments cycles using frozen oocytes more than doubling in the UK since 2013. Studies of thawed vitrified oocytes have shown similar success rates and outcomes compared to fresh, allowing the technique to be considered safe and effective. However, vitrification and thawing subjects the oocyte to stress and osmotic changes that may be evident in alterations in the timing of their morphological events. Analysis of morphokinetic markers using time-lapse incubators was performed to investigate this.

Study design, size, duration

Matched cohort study. A total of 823 embryos were analysed, 414 embryos from fresh oocytes and 409 from vitrified. The embryos were from the 288 ICSI treatment cycles performed at LWC in 2019. Fresh oocytes were from women less than 35 years old undergoing fertility treatment and vitrified oocytes were from egg donors under 35.

Participants/materials, setting, methods

Embryos graded AA, BB, BA, AB, were selected and annotated retrospectively on the Embryoscope for the following events: pronuclei appearance (tPNa) and disappearance (tPNf), time until two (t2), four (t4) and eight cells (t8), compaction initiation (tSC), the start of blastulation (tSB) and time to expanded blastocyst (tEB). PN duration, second and third embryo cell cycle (ECC), compaction and blastulation duration were also calculated as well as differences in clinical outcomes.

Main results and the role of chance

Embryos derived from vitrified oocytes (EVO) were observed to have a statistically significant delay in 4/8 morphokinetic events studied: t4 (p = 0.03), t8 (p < 0.01), tSC (p < 0.01) and tSB (p = 0.01). A mean delay of 1h50min was observed when compared to embryos from fresh oocytes (EFO). ECC duration showed a statistically significant difference with a delay of 48 minutes in the vitrified group. However, compaction occurred on average just 84min faster in this group, meaning no differences were observed in the time needed to achieve a full expanded blastocyst.

Regression analysis revealed a correlation between the age of the oocyte and morphokinetic timings. Oocytes from older women demonstrated slower development, with age having a statistically significant impact in the following categories: tPNa, tPNf, t2 and t4.

No differences found between fresh and vitrified groups in fertilization rate (80% EFO vs 79% EVO) (p = 0.841), embryo utilization rate (60% EFO and 61% EVO) (p = 0.432), implantation rate (54% EFO vs 52% EVO) (p = 0.837) and clinical pregnancy rates (49% EFO vs 42% EVO) (p = 0.502).

Limitations, reasons for caution

Limitations of the present study include the retrospective analysis, small sample size and the lack of adjustment for potential contributory/confounding factors such as semen quality, body mass index (BMI), antimüllerian hormone (AMH) levels, type of ovarian stimulation or type of infertility which are known possible influencers of embryo morphokinetics.

Wider implications of the findings

The delay observed at the cellular stage by EVO had no impact on the time the embryos needed to achieve full expansion. While vitrification affects embryo morphokinetics, it does not seem to impact the ability of the oocyte to be fertilized, activated, or to produce a viable blastocyst and pregnancy.

Trial registration number

Not applicable

P-592 The effect of ethnicity on ovarian stimulation outcomes of altruistic oocyte donors from the largest UK vitrified egg bank: a retrospective cohort study

Study question

Are there differences in ovarian stimulation outcomes among different ethnicities in the largest UK vitrified oocyte donation programme?

Summary answer

No significant differences were observed in ovarian response between non-White and White ethnic donor groups. Only AMH and baseline AFC correlated well with ovarian response.

What is known already

Ethnic disparities in ART outcomes have received much attention recently. Studies based on national registries have reported inferior outcomes for South Asian and Black ethnicities undergoing non-donor IVF treatment. Ovarian response has also been reported to differ across ethnicities, which was attributed to genetic or environmental factors, but also ethnic differences in ovarian reserve markers and body weight. A few US studies have evaluated recipient outcomes in oocyte donation treatment and found lower success rates for Black recipients. So far, no large study has evaluated the effect of ethnicity on ovarian response in a large cohort of oocyte donors.

Study design, size, duration

All consecutive oocyte donation cycles (n = 1.421) from the UK’s largest, private vitrified egg bank between 2017 and 2021 were included in this retrospective cohort analysis. Donors underwent general health evaluation, ovarian reserve (AMH, AFC) and infectious disease screening. Ovarian stimulation with recFSH was commenced on cycle day 2-3, with starting doses ranging from 112.5-450 IU. GnRH antagonist was given from day 6, and final oocyte maturation was triggered with a GnRH agonist (0.5 ml buserelin).

Participants/materials, setting, methods

Altruistic oocyte donors (n = 1.027) were stratified according to ethnicity; White (77%), mixed (7.4%), Black (5.4%), South-Asian (4.1 %), other Asian (3.5%) and South American (2.2%). In a univariate analysis, Kruskal-Wallis test was applied to compare age, BMI, AMH between ethnic groups and total and mature oocyte number during treatment cycles. In a multi-variate analysis, the effect of ethnicity, age, BMI, AMH and baseline AFC was evaluated on the number of total and mature oocytes obtained.

Main results and the role of chance

Univariate analysis showed no difference between ethnic groups in BMI (total average:23.5±3.1) AMH (total average:29.5±16.0 pmol/L) whereas other Asians were older (30.5±4.6 years, p < 0.001) and South Americans younger (24.4±4.7 years, p = 0.005) compared to Whites (27.1±4.6 years). The total number of eggs retrieved did not differ significantly between ethnic groups; White:19.6±9.1, mixed:19.6±9.0, Black:20.1±10.3, South-Asian:18±8.3, other Asian: 17.6±8.8 and South American:17.7±8.4, p = 0.24). The same applied to mature eggs obtained: White:14.2±7.1, mixed:13.9±7.2, Black:12.7±7.1, South-Asian:13.4±7.1, other Asian: 13±7.2, South American:12.8±7.1, p = 0.19). However, oocyte maturity rate was significantly lower in Black compared to White donors (64±19% vs 73±18%, p = 0.003). In a multivariate analysis, only baseline AFC (p < 0.0001) and AMH (p < 0.0001) correlated well with either the number of retrieved total or mature eggs.

Limitations, reasons for caution

Retrospective cohort studies might have inherent biases that make comparisons difficult. Slightly different inclusion criteria (age, AMH) for different ethnicities might have affected ovarian stimulation outcomes. The size of some subgroups was too low to yield statistically meaningful results. Some baseline donor variables were not included in our analysis.

Wider implications of the findings

Ovarian response outcomes were not substantially different across various ethnic groups of altruistic, UK oocyte donors. This study indicates that reported ethnic differences in IVF outcomes is unlikely to be due to response to ovarian stimulation. Donor egg programs can anticipate similar numbers of eggs irrespective of donor ethnicity.

Trial registration number

n/a

P-206 Could day 7 embryo culture become standard practice to improve patients’ treatment and outcome?

Study question

What are the clinical outcomes following transfer of day 7 embryos; could day 7 embryo culture become part of standard embryology practice?

Summary answer

Although clinical outcomes remain low, success has been seen following transfer of day 7 embryos. Extended culture plays an important role in standard embryology practice.

What is known already

In vitro culture conditions and cryopreservation techniques have improved greatly in recent years, allowing for extended culture, and freezing of embryos at the blastocyst stage. Optimally, embryos should develop to the blastocyst stage on day 5, however deviation from normal development can sometimes occur due to problems in either the embryonic intrinsic factors or imprinting timings. Live births have been reported from slower developing day 7 embryos. Extended culture to day 6 is standard practice in most IVF laboratories, however the aim of this study is to investigate the outcomes following prolonged embryo culture to day 7.

Study design, size, duration

This is a retrospective analysis study of 47 patients who underwent frozen embryo transfers (FETs) with a cryopreserved day 7 embryo at a UK licensed centre between 2017-2021. Patients were split into two groups: those transferring untested (non-PGT-A) day 7 embryos, and those transferring euploid PGT-A tested day 7 embryos. Clinical pregnancy (CPR) was analysed to study the clinical outcome of day 7 embryo culture followed by a frozen transfer.

Participants/materials, setting, methods

All patients who had FET with a day 7 embryo between 2017-2021 were included in this study. A total of 49 FETs (48 eSET,1 DET) involving 47 patients took place: 38 with untested embryos and 11 with euploid embryos. Clinical pregnancy rate (CPR) and live birth (LBR) was analysed to study the efficacy in transfer of day 7 embryos and the two groups of patients (untested and PGT-A tested) were compared.

Main results and the role of chance

The overall CPR per embryo transfer was 8% (47 patients, 49 ETs, 50 embryos transferred) and the LBR per embryo transfer was 4%. In the PGT-A group, a total of 201 day 7 embryos were biopsied over the 5-year study period; 28 were euploid following testing (14% euploidy rate). Of these, 11 have been transferred; 4 resulted in a pregnancy and 2 in a live birth. (LBR 18%) There is a significant difference in CPR between the PGT-A group (11 patients, 11 FETs; 11 embryos transferred, 4 foetal hearts seen, CPR=36%) and the untested group (36 patients, 38 ETs; 39 embryos transferred, CPR=0%) Chi square test performed and confirmed (p < 0.001). The mean age of the patient at the time of embryo transfer was 38.6 ± 0.5 and the mean age of the embryo transferred was 35.6± 0.5 (this was the patient’s age at the time of embryo freezing).

Limitations, reasons for caution

Limiting factors include the retrospective study design and the small sample size. It is also worth noting the high number of day 7 embryos required to undergo PGT-A testing to result in a low number of euploid embryos suitable for embryo transfer.

Wider implications of the findings

This study indicates the value of day 7 embryo culture as it has resulted in some patients achieving an ongoing pregnancy and a live birth. However, care must be taken to counsel patients appropriately around the chance of success when transferring day 7 embryos, particularly patients using untested embryos.

Trial registration number

Not Applicable

P-116 Clinical predictors of live birth rate (LBR) in donor-intrauterine insemination (D-IUI) cycles

Study question

Which clinical parameters can predict LBR in D-IUI cycles?

Summary answer

Only age returned as a clinical predictor of D-IUI LBR. Total motile sperm count for insemination (TMSC) and stimulation protocol may help clinicians optimise LBR.

What is known already

D-IUI cycles are a popular treatment option for patients requiring male gamete donation. For both patient and clinician, identification of parameters that can guide clinical decision-making during fertility treatment is important to optimise clinical outcomes. To date, few studies have investigated D-IUI cycle parameters with live birth as the primary outcome. Moreover, previous studies can be limited from lack of control of covariates, as well not accounting for data skewing from inclusion of multiple cycles per patient.

Study design, size, duration

A retrospective analysis of 1925 D-IUI cycles in 638 patients between 2018-2020 at a single UK-based centre was performed. All donors were recruited by the London Sperm Bank as per the HFEA regulations. Inclusion criteria for donor sperm quality were all samples that met the WHO criteria. Exclusion criteria were cycles where live birth outcome was unknown.

Participants/materials, setting, methods

Patients underwent natural or stimulation cycle. Stimulation included clomiphene or letrozole, gonadotrophins +/- GnRH agonist, an hCG trigger or LH-monitoring to time insemination and micronised vaginal progesterone for luteal support. Insemination was scheduled 24 hours following surge detection/trigger administration. TMSC is presented per 0.5ml vial, which is post-preparation sample for insemination. T-test for continuous variables and Fisher’s Exact test for categorical variables were performed. For multivariate analysis, a generalised mixed effects logistic regression was performed.

Main results and the role of chance

Median cohort age was 36 ± SE 0.1, median TMSC was 14x106 ± SE 0.2x106. Of recipients, 53% were same sex couples, 41% were single women, 6.3% were heterosexual couples. There was no significant difference in TMSCs between cycles that produced a live birth and those that did not (14x106 and 13.9x106 respectively, P = 0.1). Dividing TMSC into 5x106 increments demonstrated that small increases in LBR per cycle occurred between 2.5-25x106. On average, LBR increased by 1.3% with each increment up to 25x106, reaching 15%. Beyond this, no further increase in LBR was observed. However, these incremental increases were not statistically significant (P = 0.6). Gonadotrophin stimulation (without agonist) achieved significantly higher LBRs than all other protocols (17.1%, P < 0.001). This persisted when stratifying by age (<35; 30%, 35-37; 29%, 38+; 12.6%). A mixed effects logistic regression model demonstrated that only age returned as a significant negative predictor of LBR (aOR 0.9, 95% CI 0.86-0.94, P < 0.001). There was no effect of TMSC on LBR (aOR 1.0, 95% CI 0.99-1.02, P = 0.7). Gonadotropin stimulation was associated with over double increased odds of achieving a live birth, which came close to significance (aOR 2.29, 95% CI 0.98-5.4, P = 0.06).

Limitations, reasons for caution

The choice of management regimen could have been influenced by uncontrolled factors, introducing bias in this retrospective study. Other semen parameters were not included in the multivariate analyses which could, in turn, have affected live birth outcome, which should be considered.

Wider implications of the findings

These findings demonstrate that increasing TMSC may be associated with small rises in LBR up to 25x106 in D-IUI cycles. While gonadotrophin stimulation appeared most effective, only age was shown to be an independent predictor of LBR. Collectively, these parameters may assist clinicians in optimising LBR in D-IUI cycles.

Trial registration number

None

P–136 Factors predicting clinical outcomes of 511 recipients of vitrified oocyte donation from an UK-regulated egg bank

Study question

Do established donor and recipient clinical markers predict recipient clinical pregnancy and live birth rates (LBRs) in a vitrified oocyte donation programme?

Summary answer

Recipient BMI and previous miscarriages predicted cumulative LBR. Likelihood of clinical pregnancy and LBR was higher in recipients of donors aged 23–29 than donors 18–22.

What is known already

The influence of age on ovarian reserve underlies the upper limit of 35 years for UK donors. However, recent evidence suggests that oocyte aneuploidy rates follow an inverse U-shaped curve in relation to a woman’s age. Conflicting evidence exists regarding the impact of other donor-related factors including BMI, AMH, oocyte yield and prior reproductive history on recipient outcomes. Moreover, the effect of recipient age, BMI, and reproductive history on oocyte donation outcome remains unclear.

Study design, size, duration

Retrospective cohort study of 325 altruistic oocyte donors matched to a total of 511 recipients. Only first donations taking place between January 2017 and December 2019 were included.

Participants/materials, setting, methods

All oocyte donors were altruistic volunteers aged 18–35 with no prior infertility diagnosis. Donor and recipient screening for suitability and safety was carried out according to the Human Fertilisation Embryology Authority guidelines. Backward stepwise logistic regression was used to identify donor, recipient and embryology parameters predictive of recipient primary outcomes defined as clinical pregnancy and live birth, either cumulative or after the first embryo transfer (ET).

Main results and the role of chance

A total of 705 fresh and frozen/thawed ETs were performed, of which 76% were elective single embryo transfers (eSETs) of blastocysts (96.5%), resulting in a cumulative clinical pregnancy and LBR of 83.5% and 70.5% respectively after 3 ETs. Recipient BMI and previous miscarriages were predictors of cumulative LBR (p < 0.05). The ratio of transferrable embryos per oocytes received/fertilised and the number of ETs needed to achieve the intended primary outcome were predictors of cumulative clinical pregnancy and LBR (p < 0.05). Donor age 18–22 was associated with lower incidence of recipient clinical pregnancy and live birth after the first ET, as compared to donor age 23–29 (p < 0.05).

Limitations, reasons for caution

The present study included only healthy oocyte donors, thus conclusions may not apply to subfertile or less healthy women. Male factors were not accounted for.

Wider implications of the findings: We demonstrate the efficacy of vitrified oocyte donation treatment and identify recipient BMI, previous miscarriages and embryology parameters as predictors of cumulative LBR. Additionally, the choice of donors aged 18–22 instead of older donors is found not to be advantageous for increasing the chance of clinical pregnancy and live birth.

Trial registration number

Not applicable

P–690 Clinical predictors of a high oocyte maturation rate in IVF treatment cycles

Study question

Which clinical parameters predict a high oocyte maturation rate in patients undergoing IVF treatment?

Summary answer

Time between oocyte collection and insemination demonstrated significant association with oocyte maturation and represents a parameter that could be optimised in IVF cycles.

What is known already

Oocyte maturation is an important factor determining IVF outcomes and can be a rate-limiting step for patients undergoing treatment. A number of clinical and laboratory variables may affect this process, including the choice of trigger prior to oocyte collection, and certain laboratory procedures. Identification of which of these are predictors of maturation in individual centres enables local protocols to be optimised.

Study design, size, duration

This is a retrospective study of 714 oocyte collections from 661 women between January 2020 to November 2020 treated in a large, single centre in the UK. Subsequent fertilisation on fresh oocytes consisted of 371 IVF and 343 ICSI cycles.

Participants/materials, setting, methods

Patient and treatment data was collected by clinical staff at time of treatment. Either GnRH agonist, hCG or double trigger were administered 36 hours before collection. Prior to ICSI, oocyte maturation was assessed by visualisation of polar body (PB) extrusion. After IVF, the number of 2PNs plus unfertilised oocytes with PB extrusion were assessed. Univariate analyses consisted of Mann-Whitney test, t-test, Fisher’s Exact test or ANOVA. Potential predictors were investigated by logistic regression.

Main results and the role of chance

The end point was maturation rate, defined as high (greater or equal to 70%) or low (less than 70%). Factors predictive of a high rate included insemination more than 4 hours after collection. Oocytes inseminated over 4 hours post-collection displayed significantly higher maturation rates than oocytes inseminated less than 2 hours after collection (69% and 61% respectively; P = 0.01). Oocytes inseminated between 2–4 hours also had higher maturation than those inseminated less than 2 hours post-collection, but this did not reach significance (67% and 61%, respectively; P = 0.06). Further, oocytes fertilised by ICSI had significantly higher maturation than conventional IVF (77% and 67%, respectively, P < 0.001). No significant difference in oocyte maturation between triggers was observed. Similarly, neither age, AMH, a diagnosis of PCOS or number of oocytes collected predicted oocyte maturation in univariate analysis. Logistic regression analysis showed only time between oocyte collection and insemination (aOR 2.12; 95% CI 1.03–4.38; P = 0.04) to be a significant independent predictor.

Limitations, reasons for caution

Varying means of data collection across clinics and between clinical staff inevitably leads to provision of incomplete data and should be taken into consideration alongside interpretation. Prescription bias of specific triggers to certain patient demographics should be noted.

Wider implications of the findings: Collectively, these results suggest that greater time between oocyte collection and insemination could be recommended to IVF clinics that wish to optimise their oocyte maturation. Triggering final maturation with GnRH agonist versus hCG or dual trigger did not have a significant effect on oocyte maturation when adjusted for confounders.

Trial registration number

Not applicable

P–226 Failure of blastocoele expansion within the first two hours post thawing could halve the chances of implantation

Study question

The aim of this study was to evaluate the influence of blastocoele re-expansion time of warmed vitrified blastocysts on clinical pregnancy outcome.

Summary answer

Clinical pregnancy rate was significantly higher after transfer of warmed vitrified blastocysts that were fully expanded within 2 hours post thaw.

What is known already

The number of blastocysts being vitrified worldwide has increased dramatically over recent years. A combination of factors has led to this including the introduction of vitrification, an increase in freeze-all policies, single embryo transfer and an increase in preimplantation genetic testing. Currently, blastocyst re-expansion after thawing is used to indicate the survival status of the blastocyst and when combined with the morphology of blastocyst can predict its reproductive potential. While time taken for blastocoele re-expansion has been proposed to be a biomarker of viability, its value in clinical practice remains unclear.

Study design, size, duration

This retrospective study analysed outcomes in patients who had frozen embryo transfers between June-December 2020. 233 embryos were reviewed with time-lapse to assess their blastocoele expansion post-warming and three groups were identified. The first included fully expanded blastocysts post-warming. The second group included partially expanded blastocysts and the third non-expanded blastocysts. In addition, the groups were subcategorised into two further categories depending on whether they took less or more than 2 hours to complete expansion.

Participants/materials, setting, methods

233 vitrified/warmed embryos from 216 patients were analysed using time-lapse incubators. The first group included 134 blastocysts, of which 70 were fully expanded within 2 hours and 64 after 2 hours post thaw. The second group had 70 embryos of which 45 expanded partially within 2 hours and 25 after 2 hours. The third had 28 embryos that had no expansion within the first 2 hours (n = 20) or after 2 hours (n = 8).

Main results and the role of chance

Blastocysts were collapsed by laser prior to vitrification. Single blastocyst transfer was performed for all patients. The mean transferred embryo age was 32.1± 5.5 and the recipient’s was 37.5± 5.9. Fully expanded blastocysts (n = 70) within 2 hours demonstrated a clinical pregnancy rate (CPR) of 57% compared with 38% from those that expanded fully after 2 hours (n = 64) (p = 0.02). Blastocysts with some form of expansion (full or partial) within 2 hours post-warming (n = 115) were associated a significantly higher CPR compared to those expanding after 2 hours (n = 89). The CPR was 55% and 39% respectively (p = 0.02). Embryos that showed no expansion (n = 20) within the first 2 hours post thaw resulted in CPR of 28%. Interestingly, embryos that showed no expansion after 2 hours resulted in no pregnancy. When combining morphology as a selection criterion, expansion within 2 hours of thawing was associated with a CPR of 62.5% for ≥4AB embryos, 50% for BB embryos and 45% for poorer embryos ≤CB.In conclusion, failure of blastocoele expansion post 2 hours reduced by half the chances of clinical pregnancy (p = 0.03). Combination of the degree of re-expansion and embryo morphology is an important predictor tool to improve clinical outcomes in frozen embryo transfers.

Limitations, reasons for caution

This study uses a small sample size of patients. The data are observational and were retrospectively analysed so unknown confounders could not be assessed. The addition of more cycles and further multivariate analysis, is essential for confirmation of the findings. However, initial results are very reassuring.

Wider implications of the findings: The degree of speed of re-expansion post warming should be used as a predictor for prioritisation of embryos for transfer. Owing to these preliminary findings there is rationale for a larger scale study combining other morphological indicators that could further assess implantation indicators and assist patient counselling

Trial registration number

Not applicable

Unique case of duplex interventricular branching from the left coronary artery

We report a rare morphological variant of the left coronary artery in this case of a female embalmed cadaver, where in the heart was nourished by double anterior and posterior interventricular arteries. These were branches of the left coronary artery and it was also observed that distribution of right coronary artery was very limited. The deceased may have been without symptoms in her life, but a prior knowledge of this kind of presentation would be very much informative to the interventional cardiologist and cardiothoracic surgeons in their protocol of treatment. This has implications for the coronary angiography and subsequent management of the ischemic heart disease.

P6438Trends of acute kidney injury following percutaneous coronary interventions

Introduction

Acute kidney injury (AKI) is a significant in-hospital complication in patients undergoing percutaneous coronary interventions (PCI) and has been shown to be associated with poor outcomes. Prior studies have shown an upward trend of AKI post PCI which may be related to a multitude of factors. In this study, we aim to discern whether the recent changes in AKI definition, awareness of risk calculators, and preventive measures have been effective in changing the inclining trend.

Methods

Patients who underwent PCI during hospitalization were identified retrospectively in the Nationwide Readmission Database (NRD) from January 2010 to December 2014. All patients older than 18 years were included in the current study. Patient demographics and comorbidities were identified using appropriate ICD-9 codes. The primary outcome is the temporal trends of AKI following PCI and secondary outcomes are temporal trends in mortality, length of stay and hospitalization cost in patients with AKI. Continuous variables were expressed as means ± standard deviation or median (IQR), and categorical variables were expressed as percentages (%). All statistical tests were two-sided.

Results

Among the 2,712,473 patients who underwent PCI from 2010 to 2014, 162,286 (6%) patients developed AKI post PCI. Mean age was 69.22±12.34 years and 65% of them were males. The percentage of cases with AKI rose almost twofold from 2010 to 2014 (4.8% to 8.1%, p-value <0.005), despite the lack of a significant change in patient's demographics and comorbidities over the years. Among patients with a history of Chronic Kidney Disease (CKD) the incidence of AKI increased from 20.3% to 24.2%, and in patients without CKD history the incidence of AKI almost doubled (2.6% to 5.0%) from 2010 to 2014. There was a slight decrease in in-hospital mortality (9.4% to 8.8%) and median length of stay (7 days to 5 days), and a slight increase in the mean cost of hospitalization ($124,755.1 to $133,902.17) from 2010 to 2014.

AKI Incidence and mortality trend

Conclusion

This large cohort study shows a consistent uptrend of AKI in patients undergoing PCI from 2010 to 2014. Despite this, the mortality and length of stay are decreasing while the cost of hospitalization only slightly increased in patients with AKI. Thus, future drives to implement renal protective measures and advanced studies to identify new preventive therapies are needed to reduce the incidence of AKI post-PCI.

P5331Aspirin use for prevention of cardiovascular events in patients with high lipoprotein(a): a population-based study

Background

High lipoprotein(a) [Lp(a)] levels have been shown to increase Myocardial Infarction (MI) and all-cause mortality. However, studies evaluating the optimal preventive measures for that subset of cardiac patients are scarce. This study aims to study the outcomes of aspirin use versus no aspirin for the prevention of all-cause mortality and myocardial infarction in patients with high Lp(a) levels.

Purpose

We sought to determine the effect of Aspirin in reducing the rate of MI and all-cause mortality among patients with high lipoprotein(a) [Lp(a) ≥50mg/dL]

Methods

Patients who attended the preventive cardiology clinic from 2005 to 2016 and included in the Preventive Cardiology Database were included in the current single-center, retrospective, observational cohort study that was conducted according to the guidelines of the STROBE (Strengthening the Reporting of Observational Studies in Epidemiology Statement) checklist. The primary outcome was the incidence of myocardial infarction and the secondary outcome was all-cause mortality. Patients were excluded in cases of I) Lp(a)a <50mg/dL, II) history of malignancy, or III) being on anticoagulation/ dual antiplatelet therapy. The median duration of follow-up was 92 months from time of Lp(a) measurement to the last follow-up. Continuous variables were expressed as means ± standard deviation or median (IQR), and categorical variables were expressed as percentages (%). All statistical tests were two-sided. A propensity score-matched analysis was performed with 1:1 nearest match for Age, Gender, Race, Smoking status, BMI, Diabetes, Peripheral artery disease, Carotid artery disease, coronary artery disease, chronic kidney disease, Heart failure, Hypertension, Dyslipidemia, Stroke, family history of coronary artery disease, Lp (a), LDL, HDL, Triglycerides, glucose and total cholesterol.

Results

1,805 patients fulfilled the inclusion and exclusion criteria out of 7,410 patients initially identified with recorded Lp(a) levels in the Preventive Cardiology Database. Of these, 376 patients were taking aspirin, and 1429 patients were not receiving aspirin. After propensity score matching for different baseline characteristics and comorbidities as mentioned above, 316 patients were matched in each group. Patients who were on Aspirin had a significantly lower rate of MI events compared to patients who were not on aspirin (6.96% vs 12.02%, P=0.03) and a lower rate, however statistically non-significant, of all-cause mortality (2.84% vs 4.11%, P=0.385).

Conclusion

The use of aspirin in patients with elevated Lp(a) levels significantly lowers the rate of myocardial infarction events. Larger randomized clinical trials are warranted to evaluate the use of aspirin for primary and secondary prevention of major adverse cardiovascular events in patients with high Lp(a) levels.

P6525Impact of acute arrhythmias on in-hospital mortality in patients undergoing angioplasty

Introduction

Arrhythmia is one of the most common complications in patients undergoing percutaneous coronary interventions (PCI). Prior attempts to address these arrhythmias “aggressively” did not show improvement in survival. This study aims to investigate the impact of acute arrhythmias on in-hospital mortality in patients undergoing angioplasty in the United States.

Methods

Data about patients undergoing PCI between January 2010 and December 2014 on the Nationwide Readmission Database (NRD) was queried from the Healthcare Cost and Utilization Project (HCUP). All patients undergoing PCI were identified with the appropriate ICD-9 procedure codes. Binominal logistic regression testing was utilized to perform a multivariate analysis and different patient baseline characteristics were adjusted for including age, gender, LOS, diabetes mellitus, hypertension, renal failure, and cancer diagnosis. Odds Ratio (OR) of in-hospital mortality following acute arrhythmia were reported alongside 95% Confidence Intervals (CI).

Results

A total of 2,712,078 patients underwent PCI during hospitalization from January 2010 to December 2014. Out of those, 56,985 (2.1%) patients died while hospitalized. Most of the patients who died were older (mean age 70.73±12.9) and males (59.3%). After adjusting for age, female gender, hypertension, diabetes, heart failure, anemia, malignancy, psychiatric disorder, and longer length of stay; ventricular and supraventricular arrhythmias were found to be predictors of in-hospital mortality. Atrial fibrillation had an OR of 1.588 (95% CI: 1.551–1.626), ventricular tachycardia an OR of 2.191 (95% CI: 2.133–2.250), and ventricular fibrillation an OR of 4.143 (95% CI: 4.031–4.258).

Conclusions

Ventricular and supraventricular arrhythmias are independent predictors of in-hospital mortality following angioplasty. Further studies are warranted to evaluate the optimal management for patients with acute arrhythmia following PCI.

Toward point-of-care assessment of patient response: a portable tool for rapidly assessing cancer drug efficacy using multifrequency impedance cytometry and supervised machine learning

We present a novel method to rapidly assess drug efficacy in targeted cancer therapy, where antineoplastic agents are conjugated to antibodies targeting surface markers on tumor cells. We have fabricated and characterized a device capable of rapidly assessing tumor cell sensitivity to drugs using multifrequency impedance spectroscopy in combination with supervised machine learning for enhanced classification accuracy. Currently commercially available devices for the automated analysis of cell viability are based on staining, which fundamentally limits the subsequent characterization of these cells as well as downstream molecular analysis. Our approach requires as little as 20 μL of volume and avoids staining allowing for further downstream molecular analysis. To the best of our knowledge, this manuscript presents the first comprehensive attempt to using high-dimensional data and supervised machine learning, particularly phase change spectra obtained from multi-frequency impedance cytometry as features for the support vector machine classifier, to assess viability of cells without staining or labelling.

Acceptability of Mental Health Facilities and De-addiction Centers in India

Not much is known about disease prevalence, treatment outcomes, trained manpower, programs, and patients’ awareness of diseases from South Asia, compared with the Western world. While other aspects are improving, the quantitative evaluation of awareness of diseases is lagging. Compared with other diseases, the situation for mental health disorders and addiction is worse. While no single study can fully quantify all aspects of awareness, a good starting point is to understand if increasing the number of mental health facilities is beneficial by understanding people’s perception toward the likelihood of contracting various diseases, their preferred approach to treatment, and their perception of whether there are enough current facilities. We surveyed over 8000 families across several states of India and asked if they would treat a particular problem at home, visit a local healer, seek religious council, or go to a modern hospital for treatment. Our questions also included non-medical options to assess how likely people are to avoid trained medical help. We also asked people about their perceived likelihood of a family member ever suffering from (1) diarrhea, (2) high fever, (3) alcoholism, and (4) schizophrenia and other mental health problems. We reversed the order of diseases in our questions for a fraction of the population to evaluate the effect of order of questioning. Finally, we asked, if people feel they have enough local healers, religious places, general hospitals, de-addiction centers, and mental health facilities. Despite the taboo around mental health, many people claimed that their family members were unlikely to contract mental health or addiction problems, people recognized the severe paucity of mental health facilities and de-addiction centers. This raises hope for improving the mental health situation in India. We also found a significant relation between education levels and choices people make, underscoring the positive role education has in improving mental health.

Fully integrated wearable impedance cytometry platform on flexible circuit board with online smartphone readout

We present a wearable microfluidic impedance cytometer implemented on a flexible circuit wristband with on-line smartphone readout for portable biomarker counting and analysis. The platform contains a standard polydimethylsiloxane (PDMS) microfluidic channel integrated on a wristband, and the circuitry on the wristband is composed  of a custom analog lock-in amplification system, a microcontroller with an 8-bit analog-to-digital converter (ADC), and a Bluetooth module wirelessly paired with a smartphone. The lock-in amplification (LIA) system is implemented with a novel architecture which consists of the lock-in amplifier followed by a high-pass filter stage with DC offset subtraction, and a post-subtraction high gain stage enabling detection of particles as small as 2.8  μm using the 8-bit ADC. The Android smartphone application was used to initiate the system and for offline data-plotting and peak counting, and supports online data readout, analysis, and file management. The data is exportable to researchers and medical professionals for in-depth analysis and remote health monitoring. The system, including the microfluidic sensor, microcontroller, and Bluetooth module all fit on the wristband with a footprint of less than 80 cm2. We demonstrate the ability of the system to obtain generalized blood cell counts; however the system can be applied to a wide variety of biomarkers by interchanging the standard microfluidic channel with microfluidic channels designed for biomarker isolation.

Neonatal and obstetric outcomes of in vitro fertilization (IVF) and natural conception at a Chinese reproductive unit

In vitro fertilization (lVF) has been associated with an increased risk of preterm delivery, caesarean delivery, low and very low birth-weight infants. The authors investigated the possible high risks of adverse health outcomes in infants conceived using IVF and intracytoplasmic sperm injection (ICSI). The present study includes 443 infants born to 424 women who conceived naturally and 694 infants born to 536 women that had IVF or ICSI. The study was conducted in the Department of Obstetrics at the Yu Huang Ding Hospital from 2008 to 2009. The main outcome measures were:gestational age, birth weight, mode of delivery, multiple pregnancy rates, and baby gender. The results showed significant differences between the neonatal and obstetric outcomes of IVF/ICSI and natural conception pregnancies. When referred to singletons only, there were no major differences seen in the neonatal and obstetric outcomes between the IVF and the control group.When the IVF group was divided into two sub-groups according to the patient's age (< 35 and > or = 35 years), there was no statistically significant difference between the two groups in the observed outcomes.

Loss of WT1 expression in the endometrium of infertile PCOS patients: a hyperandrogenic effect?

CONTEXT

In fertile patients the endometrial Wilms tumor suppressor gene (WT1) is expressed during the window of implantation. Polycystic ovary syndrome (PCOS) patients suffer from hyperandrogenemia and infertility and have elevated endometrial androgen receptor (AR) expression. WT1 is known to be down-regulated by AR. Therefore, the expression of WT1 and its targets may be altered in PCOS endometrium.

OBJECTIVE

The objective of the study was to assess the expression and regulation of WT1 and selected downstream targets in secretory endometrium from ovulatory PCOS (ovPCOS) and fertile women.

DESIGN AND PATIENTS

Endometrial samples were obtained from 25 ovPCOS and 25 fertile patients.

MAIN OUTCOME MEASURE

Endometrial expression of WT1 and selected downstream targets were assessed by immunohistochemistry and RT-PCR. The androgen effect on WT1 expression was determined in vitro by immunoblots and RT-PCR. The expression of WT1 and its targets was quantified in fertile and ovPCOS stromal cells in the presence of androgens by RT-PCR. Caspase-3/7 activity was measured to evaluate sensitivity to drug-induced apoptosis.

RESULTS

WT1 expression was down-regulated in secretory-phase ovPCOS endometrium. Stromal expression of Bcl-2 and p27 was higher, and epidermal growth factor receptor was lower in ovPCOS than in fertile patients. Endometrial stromal expression of WT1, Bcl-2, Bcl-2-associated X protein, and β-catenin was regulated by androgens. Apoptosis levels were reduced in ovPCOS samples and androgen-treated fertile samples.

CONCLUSION

WT1 expression is down-regulated in ovPCOS endometrium during the window of implantation. Androgens regulate the expression of WT1 and its targets during endometrial decidualization. The altered balance between WT1 and AR in the endometrium of PCOS patients may jeopardize the success of decidualization and endometrial receptivity.

Functional antibody deficiency in a patient with type I Gaucher disease

Gaucher disease (GD), the most common lysosomal storage disorder, demonstrates an autosomal recessive pattern of inheritance. The genetic defect in GD leads to decreased production of the lysosomal enzyme glucosylceramide hydrolase, thereby resulting in the deposition of glucosylceramide sphingolipids within multiple organ systems. Although the precise mechanisms remain unclear, GD is usually associated with chronic antigenic stimulation and hyperimmunoglobulinaemia. We report a novel case of type I GD coexisting with relatively low serum immunoglobulins, impaired antibody production, and recurrent bacterial infections in a 62-year-old male. The patient had been diagnosed with GD 30 years previously and had subsequently started enzyme replacement therapy. Since being diagnosed with GD, the patient had suffered from repeated episodes of acute bronchitis and a recent severe bout of community-acquired pneumonia that required a lengthy hospitalization. On our initial evaluation, the patient had laboratory testing that demonstrated: decreased serum IgG, IgG2, and IgA levels; reduced absolute CD3(+)/CD4(+), CD3(+)/CD8(+), and lymphocyte counts; low IgG titres to pneumococcal polysaccharide vaccine; and decreased anti-tetanus antibodies. Lymphocyte function analysis demonstrated a normal response to phytohaemagglutinin, and decreased responses to concanavalin A and pokeweed mitogen. Repeat testing after 6 months revealed normal serum immunoglobulin levels and mitogenic responses. Although the explanation for our observed transient hypogammaglobulinaemia remains unclear, this patient's clinical constellation (i.e. repeated infections, hypogammaglobulinaemia and lymphopenia, decreased post-vaccination titres, and impaired responses to some mitogens) shares overlapping features with common variable immunodeficiency (CVID).

Early experience with in vitro fertilization-embryo transfer and gamete intrafallopian transfer in a Nigerian hospital

We present our early experience with in vitro fertilisation-embryo transfer (IVF-ET) and gamete intrafallopian transfer (GIFT) in a Nigerian Hospital. Twenty-one patients were recruited, 11 patients for the IVF-ET program and 10 for the GIFT program. In the IVF program the oocyte recovery rate was 100%, the fertilization rate was 66% and the cleavage rate was 97% but no live pregnancies were achieved. In contrast, one live delivery was achieved with GIFT. These results suggest that both IVT-ET and GIFT are feasible in developing countries.

Cryopreservation of human spermatozoa: an assessment of methodology using rhodamine 123

Rhodamine 123 fluorescent labeling of the human spermatozoal midpiece was used as a means of monitoring spermatozoal viability. This simple procedure was used in three separate studies to establish differential spermatozoal survival. Twenty ejaculates of reasonable quality were taken from men attending the Cromwell Hospital IVF Clinic. These were split three ways: cultured fresh at 37 degrees C as for IVF, or frozen/thawed and then cultured at 37 degrees C after freezing in either an egg yolk-free glycerol cryoprotectant or an egg yolk citrate medium. An expected overall difference in viability between fresh and frozen/thawed spermatozoa was observed, with no significant difference between the cryoprotective abilities of the two cryoprotectants studied. Four ejaculates were either frozen/thawed in the egg yolk-free cryoprotectant or cultured fresh, and both were subsequently stored at room temperature. Fall-off in frozen/thawed spermatozoal viability was more rapid than for the fresh cultured spermatozoa, although all spermatozoa survived longer at room temperature than at 37 degrees C. Five ejaculates were split to culture their spermatozoa at 37 degrees C in media containing either human or bovine serum albumin, or human fetal cord serum. BSA proved to be the least successful of protein supplements in maintaining spermatozoal viability, with HSA and cord serum giving rise to comparable viability of spermatozoa cultured in each. RH 123 is recommended as an alternative means of assessing human spermatozoal viability, and the results arising from the use of this technique here are discussed with their particular relevance to semen freezing and preparation in IVF centers.

Ultrasonic assessment of endometrial changes in stimulated cycles in an in vitro fertilization and embryo transfer program

Four distinct patterns in the ultrasonic appearance of preovulatory endometrium can be identified and described in patients undergoing stimulated cycles in an in vitro fertilization program. Ultrasonically, this endometrial response can be seen as a quantitative change in thickness and a qualitative change in gray-scale appearance or reflectivity. The application of this additional parameter of endometrial assessment together with the conventional measurement of follicular diameter as a means of optimally timing oocyte collection has been associated with a reduction in the preoperative ovulation rate from 10.9 to 3.2%, an increase in the fertilization rate from 59.2 to 82.5%, and in a pregnancy rate per embryo transfer of 20.5% in our program without the use of hormonal assays.