Abstract

Purpose: The aim was to investigate the relationship between the presence of the meiotic spindle (MS) and zona pellucida (ZP) birefringence of MII oocytes with morphokinetics variables of derived embryos in ICSI setting. Methods: Using a polarization imaging system, the ZP birefringence and presence of MS were evaluated pre ICSI. Also, morphokinetics variables including time of second PB extrusion (tPB2), time of pronuclei appearance (tPNa), time of pronuclei fading (tPNf), time of two to eight discrete cells (t2�t8) ECC1 (t2�tPB2), cc2a (t3�t2), S2 (t4�t3) and S3 (t8�t5) as well as irregular cleavage events of 368 embryos were analyzed with time lapse monitoring (TLM). Results: t5 occurred earlier in high birefringent ZP (HB-ZP) compared with low birefringent oocytes (LB-ZP; p = 0.001). In addition, t2 happened later in invisible MS compared to visible MS oocytes (p = 0.013). There were significantly lower rates of cell fusion (Fu) in oocytes with HB-ZP and also the Fu and trichotomous mitoses (TM) together in visible MS oocytes (p = 0.005, p = 0.001 and p = 0.001, respectively). Conclusions: Both t2 and t5 timings and irregular cleavage events of embryos were correlated with ZP birefringence and MS status, respectively. So, combining the information from both oocyte polarization microscopy imaging and embryo TLM can be a useful tool for single embryo transfer (SET) program. © 2017, Springer-Verlag Berlin Heidelberg.