P-702 Secretion of beta-human chorionic gonadotropin (b-hCG) by post-implantation embryos differs according to different chromosomal status.

Abstract Study question To evaluate secretion of b-hCG hormone by human post-implantation embryos cultured in-vitro up to day 10 according their chromosomal status. Summary answer Secreted levels differs among with different load, being severely diminished in monosomic when compared either euploid or trisomic embryos. What is known already Exploring early embryo development subject growing interest because errors correct at this period might cause pregnancy losses pathologies affecting postnatal health. Down's Syndrome (DS) one the most common examples supernumerary (trisomy 21; T21) aneuploidy that leads live birth but associated pathology life while monosomy chromosome 21 (M21) more likely developmental arrest. Furthermore, conclusions extracted from our previous studies put forward idea gene and metabolite expression load (Sanchez-Ribas et al., 2019). design, size, duration This an exploratory comparative study which includes a total 33 science-donated blastocysts on 6 fertilization cycles followed preimplantation genetic test for aneuploidies. Euploid (n = 10), pure T21 13) M21 10) were included study. All blastocyst good-quality initiating hatching time vitrification. Embryos degenerated during culture not used quantifications. Participants/materials, setting, methods Euploid, thawed until 10. medium specifically designed support development. Each culture, half volume media was replaced fresh media. Levels conditioned quantified ELISA immunoassay 7, 9, Results are expressed as mean ± standard deviation. Embryo morphology tracked bright-field images. Main results role chance managed hatch completely expand blastocoel cavity, 40% failed arrested inside zona pellucida 7. On concentration secreted did differ euploid, (37,29±6,27; 36,05±6,61 27,16±9,95 ng/mL respectively). Interestingly, reported progressive time-dependent increase along showed decreasing trend, reporting end (day 7 (14,86±2,57 vs ng/mL; p < 0.05). No significant differences secretions observed between neither 9 d.p.f. (61,05±8,47 56,08±8,10 respectively) nor (74,88±6,36 71,75±7,01 However, 9. (27,11±11,45 14,86±2,57 significantly reduced (p 0.01) Besides, all developed 10, 16,67% expanded before Limitations, reasons caution research focused only development, no maternal tissues considered. Further proteins should be investigated reveal other pathways implicated healthy trophoblast proliferation. Wider implications findings Monosomic embryos, implantation failures, secrete lower show similar behavior. could become non-invasive marker track progression stages detect increased likelihood arrest miscarriage. Trial registration number Not Applicable