Embryo at morula stage.
This is how an embryo looks like four days after egg fertilisation by sperm.
It consists of 16 cells and its quality is considered as good.
By Cristina Duque Royo MSc, PhD (senior clinical embryologist), Laura Garrido BSc, MSc (embryologist) and Sandra Fernández BA, MA (fertility counselor).
Last Update: 10/29/2018