P-204 The pattern of the zygote cleavage to three cells must be considered before embryo transfer

Abstract Study question What is the clinical outcome of instant irregular cleavage (IDC) from zygote to three cells? Summary answer IDC embryos, did not develop blastocysts and acieve pregnancy; FC embryos that reached blastocyst stage exerted similar pregnancy rates as control known already Evaluation morphology one earliest embryonic stages investigated. Several grading systems were proposed based on pronuclei size NPB (nucleolus precursor bodies) distribution, thus an effective indicator embryo’s potential result in a life birth. The first highly coordinated event. Disruptive timing cleavage, named direct (DC, less than 5 hours), associated with formation poor embryo quality. Early identification pathological challenging impacts fate decision ART. design, size, duration A total 1978 fresh IVF cycles single unit analyzed 4012 studied. Only 2pn cultured exclusively time-lapse system for days included. morphokinetics their recorded, z-score analysis through day 5. We discriminated between IDC, normal pattern compared various morphokinetic parameters. also evaluated possible early predictors IDC. Participants/materials, setting, methods generated study groups according pattern: (I) Control, (n = 551); (II) FC, cells within hours 1587); (III) 922). association 138 sibling random controls was thoroughly All time lapse annotations performed by senior embryologists. Statistical SPSS software. Main results role chance mainly arrested at 3 number usable (reached suitable transfer or cryopreservation) negligible; 4/922 (0.4%). In comparison, amount 108/1587 (6.6%) usage 180/551 (32.7%). While rate which (40.35% 42.55%, respectively); pregnancy. Additionally, timetable measured PN fading differed significantly groups. Therefore, we thorough data search markers these findings. have detected significant differences analysis, reflected nucleoli, well pronuclear symmetry. Limitations, reasons caution used limited since many didn’t meet inclusion criteria (lack overlapping pronuclei, presence good quality image). Wider implications findings regarding should include cycle cleavage. Culture up will spare are fated arrest even when morphological grade acceptable. Trial registration 0043-22-MMC