How to Calculate IVF Due Date

What is IVF Due Date?

An IVF due date calculator uses embryo transfer date and embryo stage to calculate estimated delivery date. Day 5 blastocysts add 261 days; Day 3 embryos add 263 days.

Formula

Due date = Egg retrieval date + 266 days (embryo age); or Embryo transfer date + 266 days (if 5-day blastocyst transfer, add 261 days)

RetrievalDate: Egg retrieval date (Date)
DaysToAdd: Days to conception (Integer (266 for fresh, varies for frozen/transfer))
DueDate: Estimated due date (Date)

Step-by-Step Guide

1Day 5 blastocyst: EDD = Transfer date + 261 days
2Day 3 cleavage: EDD = Transfer date + 263 days
3Full term = 40 weeks from LMP equivalent
4IVF babies have same developmental milestones as natural conception

Worked Examples

Input

Day 5 blastocyst transfer: 15 February

Result

EDD = 3 November (261 days later)

Frequently Asked Questions

How does IVF dating differ from natural pregnancy?

Natural: LMP used (assumes ovulation day 14). IVF: based on exact egg retrieval/fertilization day (more precise). Due date earlier by ~2 weeks vs LMP-based if using retrieval date.

Does embryo age matter?

Yes. Day 3 embryo transfer = 263 days to due date. Day 5 blastocyst = 261 days. Frozen embryos = date of thaw. Ultrasound dating (week 8–13) confirms, can vary ±3–5 days.

When will I see a heartbeat?

Ultrasound 6–7 weeks from retrieval (5–6 weeks from transfer). Transvaginal ultrasound shows earlier. Early ultrasounds (5–6 weeks) may not show heartbeat yet; recheck at 7 weeks.

Ready to calculate? Try the free IVF Due Date Calculator

Try it yourself →