implantation

implantation, (in embryology) the process involving the attachment, penetration, and embedding of the blastocyst in the lining of the uterine wall during the early stages of prenatal development. It may be artificial or natural. Also called nidation. Kinds include eccentric implantation, interstitial implantation, superficial implantation.

Sites of ectopic pregnancy implantation (Lowdermilk et al, 2012)