Pronuclear pattern does not predict morphokinetics behavior in human embryos

Background: Embryo selection procedure depends on various morphological characteristics of the embryos. One of the characteristics is based on the assessment of pronuclear pattern. The purpose was to investigate the correlation between pronuclei (PN) morphology and morphokinetic behaviors of derived embryos with Time Lapse Monitoring (TLM) in clinical intra cytoplasmic injection (ICSI) setting.Methods: over time, PN morphology from PN appearance (PNA) to PN fading (PNF), PNF according to size, contact, number and position nuclear precursor bodies (NPBs), within each PN, in other words Z soring (Z1 to Z4) and morphokinetic variables (absolute time points, including time to 2nd polar body (PB) extrusion (SPBE), PNA, PNF time to 2 cells (t2), t3, t4, t5, t6, t7, and t8) and relative timing parameters of S1(t2-PNF), CC2 (t3-t2) and S2 (t4-t3) as well as cleavage patterns and arrest of 411embryos were evaluated using TLM.Result: There were insignificant relationship between morphokinetic variables including SBPE, PNA, PNF, t2, t3, t4, t5, t6, t7, t8, S1, CC2, S2 and Z scoring according Z1 to Z4 (p˃0.05). Also, the insignificant relationship was noticed between uneven blastomeres, reverse cleavage embryos and Z scoring (p˃0.05). However, there were significant correlations between the rates of direct and arbitrary cleavage as well as arrested embryos and Z scores in zygotes.Conclusion: PN morphology alone cannot predict early morphokinetic behavior of generated embryos. Combined PN morphology and embryo kinetic evaluation were suggested in assisted reproduction programs.

کلیدواژه ها:

Cleavage pattern ، Embryo ، Morphokinetic ، Zygote ، Z scoring