IVF Due Date Calculator

An IVF due date is calculated from your embryo transfer date. For Day 3 transfers, we add 263 days. For Day 5 (blastocyst) transfers, we add 261 days. This accounts for the embryo's age at the time of transfer.

The calculation method differs because we know the exact date of conception (or very close to it) with IVF. A standard LMP calculation assumes ovulation on day 14, which may not be accurate. IVF dates tend to be more precise because the embryo's age is known.

A Day 5 embryo (blastocyst) is 2 days more developed than a Day 3 embryo at the time of transfer. So for a Day 3 transfer, we add 263 days, and for Day 5, we add 261 days — the 2-day difference accounts for the extra development.

IVF due dates are generally more accurate than LMP-based calculations because the date of conception is precisely known. However, only about 5% of babies arrive on their exact due date regardless of conception method. Your healthcare provider may adjust your due date based on ultrasound measurements.

No, the due date calculation is the same for fresh and frozen transfers. What matters is whether it's a Day 3 or Day 5 embryo, not whether it was fresh or frozen. The embryo's developmental stage at transfer is the key factor.