IVF due dates are calculated differently from natural conception. This calculator works for 3-day cleavage transfers, 5-day blastocyst transfers, and egg retrieval dates.
Unlike natural conception, IVF embryo age at transfer is precisely known, so due dates can be calculated exactly.
5-day blastocyst transfer: Add 261 days to transfer date (equivalent LMP = 17 days before transfer).
3-day cleavage transfer: Add 263 days (equivalent LMP = 19 days before transfer).
Day 0 — egg retrieval: Add 266 days (equivalent LMP = 14 days before retrieval).
Your clinic's dating ultrasound at 6–8 weeks will give the most accurate confirmation. Always follow your clinic's guidance above any calculator result.