Embryo Grading

During IVF, the embryos are cultured for up to six days and receive quality grades each day.

Egg Retrieval and Insemination Day 0

Egg maturity is important because a mature egg has the best chance of being fertilized. There are three different stages of egg maturation: Germinal vesicle (GV): The egg has not begun meiosis yet, so it is considered immature.

Metaphase I (MI): The egg is in the first phase of meiosis; however, it is still not completely mature because it has not entered the second phase of meiosis. This kind of immature egg may mature after a couple of hours of temperature-controlled incubation.

Metaphase II (MII): The egg is in the second phase of meiosis and is mature. Eggs at this stage of maturity are ready for fertilization.


  • Clear cytoplasm/normal shape
  • Single distinct polar body
  • Clear/thin zona pellucida


  • Slightly grainy cytoplasm/misshapen
  • Fragmented/abnormal polar body
  • Slightly pigmented/amorphous zona
  • Cytoplasmic bodies
  • PV debris


  • Dark/grainy cytoplasm/misshapen>1 polar body structure
  • Pigmented/thickened zona
  • Vacuoles
  • PV debris