Pregnancy IVF / FET Due Date Calculator
Created by: Olivia Harper
Last updated:
Calculate estimated due date and gestational age for IVF and frozen embryo transfer pregnancies using transfer date and embryo stage.
Pregnancy IVF / FET Due Date Calculator
PregnancyCalculate IVF and FET pregnancy due dates and gestational age from transfer date and embryo stage rather than an LMP estimate.
What is a Pregnancy IVF / FET Due Date Calculator?
A pregnancy IVF / FET due date calculator estimates due date and gestational age from embryo transfer timing rather than from a menstrual cycle estimate. Because the transfer date and embryo stage are known, IVF and FET dating is often more straightforward than LMP-based dating.
That makes this tool especially useful for people who want transfer-specific due date math without converting back through an assumed ovulation date.
The calculator also highlights why Day 3 and Day 5 transfers produce slightly different due dates for the same calendar transfer date.
How IVF and FET Due Date Math Works
The calculator uses the transfer date and embryo developmental stage to project an estimated due date. Day 3 fresh embryo transfers use a longer day offset than Day 5 blastocyst transfers because the embryo is younger on the transfer day.
If a check date is supplied, the calculator also converts the transfer dating into a current gestational age. The tool is limited to IVF and FET timing and does not duplicate standard LMP-based due date tools.
Core IVF/FET due date formulas
Day 3 fresh embryo EDD = transfer date + 263 days
Day 5 fresh blastocyst EDD = transfer date + 261 days
Frozen Day 5 blastocyst EDD = transfer date + 261 days
Current gestational age can be derived from the transfer-dated estimated due date
Example Scenarios
Example 1: Day 3 transfer
A user with a Day 3 transfer can project the estimated due date directly without reconstructing an assumed ovulation window.
Example 2: Day 5 blastocyst transfer
A blastocyst transfer date gives a slightly earlier due date than a Day 3 transfer on the same calendar day because the embryo is developmentally older.
Example 3: Current gestational age check
Adding a check date helps the user turn transfer dating into a current weeks-and-days estimate for pregnancy planning.
How People Use This Calculator
- Project due date from IVF or FET transfer timing.
- Compare Day 3 and Day 5 due-date differences.
- Check current gestational age from a transfer-based pregnancy.
- Avoid forcing IVF pregnancies into an LMP-style calculation path.
Tips for IVF Due Date Planning
Use the actual transfer date and embryo stage exactly as documented by the clinic. Small mistakes in embryo stage shift the due date by days.
Follow the official due date used by the fertility or maternity team if it differs for documented clinical reasons.
Frequently Asked Questions
Why is this different from a standard due date calculator?
IVF and FET dates are tied to known embryo transfer timing, so the due date logic is more precise than an LMP estimate and uses transfer-specific day offsets.
Why do Day 3 and Day 5 transfers produce different due dates?
The embryo is a different developmental age on the transfer day, so the projected due date shifts by two days for the same calendar transfer date.
Does frozen Day 5 differ from fresh Day 5?
No. For due-date math, frozen Day 5 and fresh Day 5 transfers use the same day-count rule.
Can I use this for natural conception?
No. This page is specifically for IVF and FET pregnancies. Natural-conception users should use the standard due date calculator instead.
Can I check my current gestational age too?
Yes. If you enter a check date, the calculator estimates current gestational age in weeks and days from the transfer-based pregnancy dating.
Sources and References
- IVF and fertility clinic due-date dating conventions.
- ACOG due-date estimation guidance applied to known conception timing.
- Patient education materials on IVF/FET pregnancy dating.
Medical Note
Pregnancy IVF / FET Due Date Calculator is for educational planning only. It does not replace obstetric, midwifery, pediatric, physiotherapy, mental health, pharmacy, or emergency care.