IVF Due Date Calculator
Use your embryo transfer date and embryo age to estimate your pregnancy due date, equivalent LMP, and milestone dates.
Most IVF transfers are Day 5 blastocysts.
How to calculate IVF pregnancy due date correctly
If you conceived through in vitro fertilization (IVF), your due date can be estimated more precisely than many spontaneous pregnancies because your clinic knows the exact transfer timing and embryo age. Instead of guessing ovulation date from a last menstrual period, IVF dating starts with a known event: embryo transfer.
The calculator above uses a standard obstetric method that converts transfer timing into a 40-week pregnancy timeline. This gives you an estimated due date (EDD) and helpful checkpoints such as 12 weeks, 20 weeks, and third trimester start.
IVF due date formula
Pregnancy due date is typically 280 days from the equivalent LMP (last menstrual period), or 266 days from fertilization. In IVF, fertilization happened before transfer, so embryo age matters.
- Due date = Transfer date + (266 − embryo age in days)
- Day 5 transfer: add 261 days
- Day 3 transfer: add 263 days
Example: A Day 5 embryo transferred on March 1 is estimated due about 261 days later.
Why IVF dating is usually more accurate
Known embryo developmental age
Clinics track egg retrieval, insemination, and embryo development. Because embryo age is documented, gestational dating is usually cleaner than dating based on cycle recall alone.
Clear timeline for ultrasounds
IVF dates also help clinicians schedule bloodwork and ultrasounds with tighter expectations for what should be visible at each stage.
Still an estimate
Even with IVF precision, the due date is an estimate, not a promise. Normal delivery timing can vary by days or weeks.
What information you need before calculating
- Embryo transfer date (not retrieval date, unless your clinic specifically instructs otherwise)
- Embryo age at transfer (Day 3, Day 5, etc.)
- Your clinic records if unsure—especially for frozen embryo transfer cycles
Common IVF due date questions
Do frozen embryo transfers change the formula?
No. Frozen versus fresh transfer does not change due-date math. The key variable is embryo age at transfer.
Can ultrasound change my due date?
In some cases, your care team may keep IVF dating even if early measurements vary slightly. Always follow your OB/REI guidance.
Is implantation day the same as conception date?
Not exactly. Conception/fertilization occurs before transfer. Implantation happens afterward and can vary by embryo and cycle conditions.
Milestones to track after IVF transfer
Many patients like to pair due-date calculation with practical milestone planning. Typical points include:
- First trimester completion (~12 weeks)
- Anatomy scan (~20 weeks)
- Third trimester start (~28 weeks)
- Early term (~37 weeks)
- Estimated due date (~40 weeks)
Tips for using an IVF due date calculator
- Double-check transfer date format before calculating.
- Select the correct embryo day from your transfer report.
- Use calculator output as planning guidance, not diagnosis.
- Confirm all timelines with your fertility or obstetric team.