Carnegie Stage 4

Introduction

Stage 4 is reserved for the attaching blastocyst that is adhering to the endometrial lining of the uterus. The attaching process is called adplantation and heralds the onset of implantation. Stage 4 embryos have an estimated postfertilization age of approximately 6 days.

Also on EHD: Arteries of the Hand

Attaching Blastocyst

Embryo attached to an endometrial cell culture