Your IVF due date
Enter the embryo transfer date and the embryo day at transfer.
Blastocyst transfer (most common). EDD = transfer date + 263 days.
Estimates based on the SART/ASRM standard formula. Actual delivery may vary by ±2 weeks. Learn more
For reference only. If your obstetrician has issued an EDD, that value takes priority.
How is it calculated?
For IVF pregnancies the EDD is calculated precisely from the transfer date and the embryo age (D3 / D5 / D6):
Formula: EDD = transfer date + (266 − embryo age in days). Example: a D5 transfer → EDD = transfer + 263 days; a D3 transfer → transfer + 261 days.
Unlike the LMP-based Naegele formula, the fertilisation and transfer dates are known exactly, so an IVF EDD is generally more accurate than a natural-conception EDD.
Limitations of this estimate
An IVF EDD is still an estimate:
- Multiple pregnancies tend to deliver before the EDD (twins ~37 weeks on average).
- Embryo grade, maternal age and conditions all shift the actual delivery.
- If a crown-rump length (CRL) on an 8-12 week ultrasound differs by ≥5 days, the OB-GYN may re-date the pregnancy.
- This calculator assumes a standard fresh / frozen transfer. Confirm with your fertility specialist for non-standard protocols.
Sources
Frequently asked
How do D3 and D5 EDDs differ?
For the same transfer date, a D3 embryo gives EDD = transfer + 261 days, while a D5 gives EDD = transfer + 263 days. So the D3 EDD is 2 days earlier.
Embryo age means how many days after fertilisation the transfer happened; D6/D7 follow the same -1 day pattern.
Is an IVF EDD different from a natural pregnancy EDD?
Only the calculation method differs — pregnancy progression is the same. Because the LMP is often induced by medication in IVF, the Naegele formula is unreliable, so the transfer-date calculation is more accurate.
If the early-ultrasound CRL differs by ≥5 days from the IVF EDD, ACOG recommends using the ultrasound EDD.