P–515 Clinical outcome of mosaic-blastocyst transfer versus euploid-blastocyst transfer in single frozen blastocyst transfer cycles

Study question

What is the clinical outcome of transferring a mosaic blastocyst versus a euploid blastocyst in single frozen blastocyst transfer (sFBT) cycles?

Summary answer

Single mosaic blastocyst transfer has similar clinical outcome to single euploid blastocyst transfer.

What is known already

Embryonic mosaicism occurs when there are two or more distinct cell lines found in preimplantation embryos derived from IVF. Data from recent studies show that mosaic blastocysts have the potential to implant and can result in healthy live births. As a result, patients now have the option of transferring mosaic blastocyst when they do not have any euploid blastocyst available for transfer. However, the clinical outcome of transferring mosaic blastocyst has not been definitively reported. Thus, a retrospective study was conducted to compare the clinical outcome of mosaic sFBT and euploid sFBT.

Study design, size, duration

A total of 602 patients underwent frozen blastocyst transfer in Alpha IVF from January to October 2019 and had their blastocysts screened for aneuploidy. These patients were divided into 2 groups: 26 patients with mosaic blastocysts transferred (Group A, age ranged 19–44), and 576 patients with euploid blastocysts transferred (Group B, age ranged 21–44). The mean age of patients from Group A and B were 34.0 and 32.8 respectively (p > 0.05).

Participants/materials, setting, methods

All samples had their DNA libraries constructed for sequencing using Next Generation Sequencing according to manufacturer’s specification (IonTorrent, USA). All blastocysts were frozen for subsequent sFBT cycle (Cryotech, Japan). All thawed blastocysts for sFBT survived with morphologically intact inner cell mass and trophectoderm cells. The importance of antenatal confirmation of the fetal chromosome status was emphasized in patients from Group A. The clinical outcomes of both groups were analysed and compared.

Main results and the role of chance

No significant differences were seen in the clinical pregnancy and implantation rate of Group A and B (65.4% vs 63.0%; p > 0.05). The miscarriage rate of Group A and B were 23.5% and 14.0% respectively. Albeit the higher miscarriage rate in Group A, there was no statistical significance between these two groups (p > 0.05).

Group A was further divided into two subgroups, Subgroup A1: low risk mosaic blastocyst transfer; Subgroup A2: high risk mosaic blastocyst transfer. In the comparison of Group A subgroups, the clinical pregnancy and implantation of Group A1 is higher than Group A2 (76.9% vs 44.4%). In addition, the miscarriage rate of Group A1 and A2 were 23.1% and 0.0% respectively. Interestingly, there was no statistical significance in clinical pregnancy rate, implantation rate and miscarriage rate between these two subgroups.

Limitations, reasons for caution

This is a retrospective study and the sample size was comparatively smaller in the mosaic blastocyst transfer group than the euploid blastocyst transfer group. Further studies with a larger sample size should be carried out to ascertain the clinical outcome.

Wider implications of the findings: Single mosaic blastocyst transfer has similar clinical outcome to single euploid blastocyst transfer. Thus, mosaic blastocyst can be considered for transfer when no euploid blastocyst are available. Nevertheless, stringent antenatal surveillance for chromosomal abnormalities to confirm the chromosomal status of the fetus must be followed.

Trial registration number

Not applicable

P–557 Trophectoderm biopsy technique and rate of mosaicism in human blastocysts

Study question

Do different trophectoderm biopsy techniques affect mosaicism rate in human blastocysts?

Summary answer

No statistical significance was found between biopsy techniques and mosaicism rate. However, an increase in mosaicism rate was observed when the flicking technique was used.

What is known already

Mosaicism is defined as two or more distinct cell lines within an embryo. Recent advances in Next Generation Sequencing (NGS) technology with an increased sensitivity allows a higher accuracy in quantification of mosaic levels in biopsied cells. The incidence of mosaicism is widely debated as there are many attributing technical and biological factors. Since, trophectoderm biopsy is a technically challenging process, it is crucial to ensure that the both biopsied cells and blastocyst suffers minimal damage during biopsy.

Study design, size, duration

This is a prospective study involving 222 patients (age range= 18–44, mean age= 31.5) who underwent IVF cycles in Alpha IVF, Malaysia from March 2019 to August 2019. Six hundred and sixty-eight (668) of the blastocysts were biopsied on Day 5 (Group 1) while 177 blastocysts were biopsied on Day 6 (Group 2). The blastocysts in these groups were further categorised into their corresponding biopsy techniques: (A) laser+pulling; (B) laser+flicking; (C) flicking only.

Participants/materials, setting, methods

Blastocysts which were at least fair graded (Gardner, 1999) were biopsied and vitrified (Cryotec, Japan). The number of biopsied cells ranged from 5 to 10 cells. All biopsied trophectoderm samples were subjected to Preimplantation Genetic Testing for Aneuploidy (PGT-A) with Next Generation Sequencing (NGS) (Ion Torrent, USA). Chromosomal mosaicism analysis was done using ReproSeq Mosaic PGS w1.1 workflow. Trophectoderm biopsied sample which were tested to have 20% to 80% aneuploid cells were reported as mosaic.

Main results and the role of chance

In Group 1, the mosaicism rates for biopsy technique A, B and C were 23.3% (104/446), 28.2% (58/206) and 37.5% (6/16) respectively. In Group 2, the mosaicism rates for biopsy technique A, B and C were 14.6% (7/48), 19.5% (23/118) and 27.3% (3/11) respectively. There were no significant differences (p > 0.05) in mosaicism rates between all study groups and subgroups.

Limitations, reasons for caution

Although no statistical significance was found between trophectoderm biopsy techniques and the prevalence of mosaicism, there is a trend of an increase in mosaicism rate when the flicking technique was used. Therefore, further studies with a larger sample size should be undertaken.

Wider implications of the findings: Our study demonstrates a trend in the decrease of mosaicism rate when laser pulses was used to loosen the cell junction of targeted cells. Hence, in place of the flicking method alone, laser pulses should be applied during trophectoderm biopsy if our findings are confirmed in a larger controlled study.

Trial registration number

Not applicable

P–150 Does trophectoderm biopsy performed on different blastocyst stages affect the clinical outcome?

Study question

The objective of this study is to evaluate the effect of trophectoderm (TE) biopsy on different blastocyst stages and its clinical outcome.

Summary answer

Our results showed that TE biopsy significantly reduced the clinical outcome of fully hatched blastocyst. What is known already: TE biopsy is a method widely practiced to harvest cells to determine the chromosomal constitution of a blastocyst, ensuring higher implantation and healthy pregnancies. The effect on clinical outcome after transferring blastocysts biopsied at different blastocysts stages has not been extensively studied.

Study design, size, duration

This retrospective study was conducted from January 2017 until July 2019 at Alpha IVF & Women’s Specialists. Following laser assisted hatching on day 3, TE biopsy was performed on unhatched, hatching and fully hatched day–5 blastocysts. A total of 1,020 single euploid blastocysts transfer (SBT) were performed. The average maternal age was 31.7. Implantation rates (IR) were evaluated for all stages of hatching (Unhatched: BG3 & 4; hatching: BG5; fully hatched: BG6).

Participants/materials, setting, methods

Laser assisted hatching (Hamilton Thorne Bioscience, USA) was performed on day–3 and subsequently cultured to blastocyst-stage. Different hatching stages were observed using embryoscope time-lapse system (Vitrolife, Sweden) and were recorded. Day–5 blastocysts with at least BG3BB grade (Gardner’s System) were selected for TE biopsy and the biopsied cells were sent for preimplantation genetic testing for aneuploidy (PGT-A) using Next-Generation Sequencing (Life Technologies, USA). All blastocysts were vitrified and warmed using the Cryotec Method (Cryotech, Japan). Main results and the role of chance: All 1,020 blastocysts survived post-warmed (post-warm survival rate= 100%) and were transferred in frozen transfer cycles. TE biopsy performed on unhatched blastocysts showed a comparable IR to hatching blastocysts (60.0% [15/25] and 65.2% [627/961]). While fully hatched blastocysts (44.12% [15/34]) show a significantly lower IR when compared to hatching blastocysts (65.2% [627/961]), no significant difference was seen when comparing unhatched blastocysts to fully hatched blastocysts (60.0% [15/25] and 44.12% [15/34]; p = 0.2949).

Limitations, reasons for caution

The sample size was comparatively smaller in the unhatched and fully hatched group than the hatching group. Further studies with a larger sample size is recommended to ascertain the clinical outcome. Since this is a retrospective study and biopsy was done by different embryologists, the biopsy technique was not controlled. Wider implications of the findings: To achieve higher clinical pregnancy, it is recommended to perform TE biopsy before the blastocysts is fully hatched.

Trial registration number

Not applicable

O-204 Is mosaicism affected by an embryologist’s experience in biopsy?

Study question

Are there any correlations between blastocyst mosaicism rate and biopsy experience among embryologists?

Summary answer

Blastocysts biopsied by embryologists with ≥1 year of biopsy experience have significantly lower mosaicism rate compared to those with <1 year of biopsy experience.

What is known already

It has been reported that the incidence of blastocyst mosaicism is highly variable between centres (PGDIS, 2019). It is also suggested that the technical aptitude of the embryologist performing blastocyst biopsy may give rise to mosaicism. Thus, a retrospective study was conducted to investigate the relationship between blastocyst mosaicism rate and biopsy experience among embryologists in Alpha IVF.

Study design, size, duration

Thirteen competent embryologists who were trained in blastocyst biopsy were included in this study: 5 have ≥1 year of biopsy experience (Group A; Embryologist A-1, A-2, A-3, A-4, A-5); 8 have <1 year of biopsy experience (Group B; Embryologist B-1, B-2, B-3, B-4, B-5, B-6, B-7, B-8). Embryologists from Group A biopsied a total of 4795 blastocysts while those from Group B biopsied 4869 blastocysts from January 2018 to December 2019.

Participants/materials, setting, methods

TE biopsy was performed either on Day 5, 6 or 7 using the laser or flicking method. The biopsied cells had Preimplantation Genetic Testing for Aneuploidy (PGT-A) analysed using Next Generation Sequencing (Ion Torrent, USA) and chromosomal mosaicism analysis was done using ReproSeq Mosaic PGS w1.1 workflow. Mosaic blastocysts were reported when 20% - 80% of aneuploid cells are tested in the biopsied samples. Only successfully amplified biopsy samples were included in this study.

Main results and the role of chance

The mosaicism rate of blastocysts biopsied by embryologists from Group A and B were 17.8% and 19.8% respectively. Blastocysts from Group A showed significantly lower mosaicism rate compared to Group B (p = 0.01). The mosaicism rates of blastocyst biopsied by Embryologist A-1, A-2, A-3, A-4 and A-5 were 17.3%, 19.1%, 16.8%, 15.2%, and 18.9% respectively. The mosaicism rates of blastocyst biopsied by Embryologist B-1, B-2, B-3, B-4, B-5, B-6, B-7, and B-8 were 17.5%, 18.6%, 22.5%, 20.4%, 27.8%, 20.6%, 20.1% and 20.3% respectively. There were no significant differences in blastocyst mosaicism rate between embryologists within Group A (p > 0.05). Contrarily, in Group B, Embryologist B-5 had a significantly higher blastocyst mosaicism rate compared to the other embryologists within the same group (p < 0.05).

Limitations, reasons for caution

Since this study is retrospective in nature, the biopsy technique (either the laser or flicking method) was not controlled. Hence, further studies to analyse the differences between these 2 biopsy techniques should be carried out to confirm its effect on the occurrence of blastocyst mosaicism.

Wider implications of the findings

Our study demonstrates that blastocysts biopsied by embryologists with ≥1 year of biopsy experience have significantly lower mosaicism rate compared to those with <1 year of biopsy experience. This indicates that the skill and experience of an embryologist in biopsy may have an impact on the mosaicism rate.

Trial registration number

Not applicable

Malaysian mothers' knowledge & practices on care of neonatal jaundice

This study aimed to determine the gaps of knowledge and practices of care of neonatal jaundice among Malaysian mothers. It was a cross sectional study of 400 mothers who attended the obstetric clinics or were admitted to the obstetric wards of a general hospital. They were surveyed with a structured set of questionnaire. The results showed that a majority (93.8%) of them knew about neonatal jaundice, and 71.7% knew that jaundice lasting more than 2 weeks was abnormal. However, only 34.3% of them were aware that jaundice appearing during the first 36 hours of life was abnormal. Less than 20% knew about glucose-6-phosphate dehydrogenase deficiency and that fetal-maternal blood group differences could cause jaundice. Although 71.7% and 69.7%, respectively, of the mothers knew that severe jaundice could cause death and brain damage, only 38.4% of them were aware that severe jaundice could result in hearing impairment. A very low proportion (27.1%) of them was aware that putting jaundiced infants under the direct sun could result in dehydration and worsening of jaundice. Out of a maximum score of 15, the mean maternal knowledge score was 7.4 (95% confidence intervals: 7.1, 7.7). Majority (83.1%) of the multiparous mothers with a past history of having children developing neonatal jaundice (n = 154) practiced placing their infants under the direct sun. This study revealed that there was a wide knowledge gap among Malaysian mothers on care of neonatal jaundice. Placing infants under the direct sun was still a common practice.

Knowledge and practice of confidential data handling in the Welsh Deanery: a brief report

Recent large-scale personal data loss incidents highlighted the need for public bodies to more securely handle confidential data. We surveyed trainees from all specialties in the Welsh Deanery for their knowledge and practice. All registered trainees were invited to participate in an online anonymised survey. There were 880 completed and non-duplicated responses (52.9% response rate). Responses were analysed using Microsoft Access. Over 40% (388/880 (44.1%)) did not use formal guidelines on storage or disposal of confidential data. The majority appeared to dispose of confidential paper documents securely, that is, using shredders and white shredder bags. However, there were significant numbers of unmarked responses. Clinical documents, such as theatre lists, were taken home by 281/880 (31.9%) of trainees. The majority secured their computers (569/871 (65.3%)) by either not keeping patient identifiable data on them or using encryption. However, 302/871 (34.7%) did not adequately secure their computers. The surgical and anaesthetic specialties were least aware of formal confidentiality guidelines (95/178 (53.4%)) and 52/102 (51.0%) respectively) and least secured their computers (106/178 (59.6%) and 63/102 (61.8%) respectively). Education is needed to improve knowledge and practice of confidential data handling. This may be delivered through workshops during induction programmes or as part of European Computer Driving Licence (ECDL) modules. Training is especially indicated for the surgical and anaesthetic specialties.

The history of extracorporeal oxygenators

Extracorporeal oxygenators are artificial devices that substitute for anatomical lungs by delivering oxygen to, and extracting carbon dioxide from, blood. They were first conceptualised by the English scientist Robert Hooke (1635-1703) and developed into practical extracorporeal oxygenators by French and German experimental physiologists in the 19th century. Indeed, most of the extracorporeal oxygenators used until the late 1970s were derived from von Schroder's 1882 bubble oxygenator and Frey and Gruber's 1885 film oxygenator. As there is no intervening barrier between blood and oxygen, these are called 'direct contact' oxygenators; they contributed significantly to the development and practice of cardiac surgery till the 1980s. Membrane extracorporeal oxygenators introduce a gas-permeable interface between blood and oxygen. This greatly decreased the blood trauma of direct-contact extracorporeal oxygenators, and enabled extracorporeal oxygenators to be used in longer-term applications such as the intensive therapy of respiratory distress syndrome; this was demonstrably beneficial for neonates but less so for older patients. Much work since the 1960s focused on overcoming the gas exchange handicap of the membrane barrier, leading to the development of high-performance microporous hollow-fibre oxygenators that eventually replaced direct-contact oxygenators in cardiac theatres.

Use of three-dimensional animation for regional anaesthesia teaching: application to interscalene brachial plexus blockade †

BACKGROUND

Using commercial computer graphics software (TrueSpace), we constructed a virtual-reality model for teaching interscalene brachial plexus block. This tool combines the clarity of schematic drawings and the clinical relevance of video clips and live demonstrations. The aim is to accelerate learning and aid retention of relevant information.

METHOD

We made a series of continuous short virtual-reality animations demonstrating the steps to perform an interscalene block. Superficial structures were made transparent to show the anatomical relevance of landmarking and needle manipulation. The clips were presented to delegates at a training course in Oxford. Delegates were surveyed to ascertain whether or not the presentation enhanced their understanding of anatomy and regional block technique. Before and after the presentation, delegates indicated surface landmarking, needle angulation, and movement on photographs of the lateral and anterolateral neck views of two volunteers. The markings were analysed by two independent assessors and rated as 'good', 'bad', or 'ungradeable'. The percentage improvement for each skill group was calculated and McNemar's test applied.

RESULTS

Of 24 respondents, the majority thought that the presentation enhanced their understanding of the anatomical (87.5%) and technical principles (79.2%) of interscalene blocks. Analysis of the marked photographs showed an overall 24.1% improvement in landmarking skills after the teaching presentation (P<0.001). Changes were significant in moderately experienced skill groups (P<0.001) but not for the very experienced (P>0.5) and the inexperienced skill groups (P<0.1). There was 76.3% concordance in scoring between the two assessors.

CONCLUSION

Three-dimensional animation is a promising new tool to accelerate the learning of regional anaesthetic techniques.