Meiotic spindle size is a strong indicator of human oocyte quality.

Purpose: To investigate the relationship between the meiotic spindle size in human metaphase II oocytes and embryo developmental potential after intracytoplasmic sperm injection (ICSI).

Methods: Analyzed were 1302 oocytes with a visible meiotic spindle from 281 patients aged under 40 years undergoing ICSI cycles. The meiotic spindle was imaged by using PolScope before ICSI.