Seeking arrangements: cell contact as a cleavage-stage biomarker

Research question: What can three-dimensional cell contact networks tell us about the developmental potential of cleavage-stage human embryos? // Design: This pilot study was a retrospective analysis of two Embryoscope imaging datasets from two clinics. An artificial intelligence system was used to reconstruct the three-dimensional structure of embryos from 11-plane focal stacks. Networks of cell contacts were extracted from the resulting embryo three-dimensional models and each embryo's mean contacts per cell was computed. Unpaired t-tests and receiver operating characteristic curve analysis were used to statistically analyse mean cell contact outcomes. Cell contact networks from different embryos were compared with identical embryos with similar cell arrangements. // Results: At t4, a higher mean number of contacts per cell was associated with greater rates of blastulation and blastocyst quality. No associations were found with biochemical pregnancy, live birth, miscarriage or ploidy. At t8, a higher mean number of contacts was associated with increased blastocyst quality, biochemical pregnancy and live birth. No associations were found with miscarriage or aneuploidy. Mean contacts at t4 weakly correlated with those at t8. Four-cell embryos fell into nine distinct cell arrangements; the five most common accounted for 97% of embryos. Eight-cell embryos, however, displayed a greater degree of variation with 59 distinct cell arrangements. // Conclusions: Evidence is provided for the clinical relevance of cleavage-stage cell arrangement in the human preimplantation embryo beyond the four-cell stage, which may improve selection techniques for day-3 transfers. This pilot study provides a strong case for further investigation into spatial biomarkers and three-dimensional morphokinetics

Direct Unequal Cleavages: Embryo Developmental Competence, Genetic Constitution and Clinical Outcome

<div><p>Objective</p><p>To investigate the prevalence, developmental potential, chromosomal constitution and clinical outcome of embryos with direct unequal cleavages (DUC).</p><p>Design</p><p>A retrospective observational study.</p><p>Setting</p><p>Academic Institution.</p><p>Participant</p><p>21,261 embryos from 3,155 cycles cultured in EmbryoScope^®.</p><p>Results</p><p>The total incidence of DUCs per embryo occupying the first three cleavages were 26.1%. Depending of the cell stage, DUC rate was 9.8% at first cleavage (DUC-1), 9.1% at second cleavage (DUC-2), and 3.7% at third cleavage (DUC-3) with 3.6% of embryos exhibiting multiple DUCs (DUC-Plus). The occurrence of DUCs was not correlated with female gamete age or source. The incidence of DUC-1 was significantly higher in embryos fertilized by epididymal and testicular sperm (13.6% and 11.4%, respectively) compared to ejaculated sperm (9.1%, all p<0.05). The total incidences of DUCs were strongly correlated with the onset of blastomere multinucleation (MNB) during the first three divisions. In MNB embryos, DUCs incidence are two to three times more likely to develop when compared to non-MNB embryos (OR = 3.11, 95% CI [2.64, 3.67] at 1-cell stage, OR = 2.64, 95% CI [2.39, 2.91] at 2-cell stage and OR = 2.51, 95% CI [1.84, 3.43] at 4-cell stage). The blastocyst formation rates gradually decreased from 61.0% in non-DUC to 40.2% in DUC-3, 18.8% in DUC-2, 8.2% in DUC-1 and 5.6% in multiple DUC embryos (DUC-Plus). The known implantation rates (FH) for day 3 (D3) transfers were 12.42% (n = 3172) in Non-DUC embryos, 6.3% (n = 127) in DUC-3, and 2.7% (n = 260) in DUC-2 embryos. No live births resulted from either DUC-1 (n = 225) or DUC-Plus (n = 100) embryo transfers. For blastocyst transfers, lower implantation rates (33.3%) but similar live birth (LB) rates (40%) were observed if DUC blastocysts were transferred. Comparatively rates in Non-DUC blastocyst were 45.2% and 34.8%, respectively. The euploid rate gradually increased from DUC-1, -2, -3 to Non-DUC (13.3%, 19.5%, 33.3%, 45.6%, p<0.001) for D3 biopsied embryos. Interestingly, the trend of decreased euploidy disappeared in DUC D5/6 biopsied embryos and similar rates were exemplified in DUC (D5 56.3%, D6 35.6%) vs. non-DUC (D5 51.4%, D6 33.8%) embryos.</p><p>Conclusion</p><p>Blastocyst formation, implantation potential and euploid rate were significantly reduced in DUC embryos. DUC embryos should be deselected for D3 transfers, but should be culture to blastocyst stage for possible ET.</p></div

Embryo development after heterotopic transplantation of cryopreserved ovarian tissue

Background: Cancer treatments, including chemotherapy, radiotherapy, and radical surgery, can induce premature menopause and infertility in hundreds of thousands of women of reproductive age every year. One of the ways to possibly preserve fertility before these treatments is to cryopreserve ovarian tissue for later transplantation. We aimed to restore fertility by cryopreservation and transplantation of ovarian tissue. Methods: Ovarian tissue was cryopreserved from a 30-year-old woman with breast cancer before chemotherapy-induced menopause, and this tissue was transplanted beneath the skin of her abdomen 6 years later. Findings: Ovarian function returned in the patient 3 months after transplantation, as shown by follicle development and oestrogen production. The patient underwent eight oocyte retrievals percutaneously and 20 oocytes were retrieved. Of the eight oocytes suitable for in-vitro fertilisation, one fertilised normally and developed into a four-cell embryo, Interpretation: Fertility and ovarian endocrine function can be preserved in women by long-term ovarian tissue banking

D3 and blastocyst transfer known implantation rate.

<p>Left: D3 transfer result. Right: Blastocyst transfer result (including frozen transfer cycles). DUC-1: direct unequal cleavage at 1^st cleavage; DUC-2: direct unequal cleavage at 2nd cleavage; DUC-3: direct unequal cleavage at 3^rd cleavage; DUC-Plus: DUC occurred more than once. Non-DUC: embryos without DUC. DUCs: all DUC embryos.</p

Incidence of DUCs per blastomere and multinucleated blastomere (MNB).

<p>Incidence of DUCs per blastomere and multinucleated blastomere (MNB).</p

Summary of preimplantation genetic screen results in day 3/5/6 biopsied DUC embryos (DUCs combined).

<p>Summary of preimplantation genetic screen results in day 3/5/6 biopsied DUC embryos (DUCs combined).</p

DUCs incidence: gamete age, gamete source and oxygen concentration.

<p>DUCs incidence: gamete age, gamete source and oxygen concentration.</p

Incidence of DUCs per embryo and multinucleation.

<p>Incidence of DUCs per embryo and multinucleation.</p

Super-Focus: Domain Adaptation for Embryo Imaging via Self-supervised Focal Plane Regression

In recent years, the field of embryo imaging has seen an influx of work using machine learning. These works take advantage of large microscopy datasets collected by fertility clinics as routine practice through relatively standardised imaging setups. Nevertheless, systematic variations still exist between datasets and can harm the ability of machine learning models to perform well across different clinics. In this work, we present Super-Focus, a method for correcting systematic variations present in embryo focal stacks by artificially generating focal planes. We demonstrate that these artificially generated planes are realistic to human experts and that using Super-Focus as a pre-processing step improves the ability of a cell instance segmentation model to generalise across multiple clinics