How it is calculated
| Transfer | Due date | Equivalent LMP |
|---|---|---|
| Day-3 embryo | Transfer + 263 days | Transfer − 17 days |
| Day-5 blastocyst | Transfer + 261 days | Transfer − 19 days |
The same applies to frozen embryo transfers: what matters is the embryo’s age at transfer.
Worked example
A day-5 blastocyst transfer on 10 April 2026: due date = 10 April + 261 days = 27 December 2026.
Frequently asked questions
When is the pregnancy test after transfer?
Usually 9–12 days after transfer with a blood beta-hCG test, as your clinic advises.
Are IVF pregnancies shorter?
Average length is about the same, but twins and preterm birth are a bit more common.
What about a day-6 embryo?
Subtract one more day: due date = transfer + 260 days.