Implantation
The process by which a blastocyst attaches to and embeds itself in the lining of the uterus.
In plain English
It's the moment the embryo actually attaches to your womb lining, usually happening a few days after transfer.
Why it matters
It's the step that has to succeed for a pregnancy to start, and it's the main focus of the two week wait after transfer.
Related terms
Guides that cover this
Written by patients, not clinicians. This page has not yet been reviewed by a named fertility professional, so it explains published guidance and points you to the original source instead of giving medical advice. It is not medical advice. Decisions about your treatment belong with your own clinic. Read our editorial policy and corrections policy.