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IVF Due Date Calculator
More precise than LMP-based math. Day-3, day-5 blastocyst, FET, and egg donor cycles all supported. Returns due date, current week, trimester, and key milestones.
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Estimated due date
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Frequently asked
266 days from estimated conception, minus the embryo's age at transfer. Day-5 blastocyst: transfer date + 261 days. Day-3 transfer: + 263 days. FET follows the same rule based on the day of the embryo at freezing. The math matches what your fertility clinic uses.
LMP dating assumes ovulation on day 14 of a 28-day cycle. Real cycles vary. IVF removes that uncertainty — fertilization timing is documented to the hour, embryo development to the day. That's why IVF pregnancies typically don't get the early-ultrasound 'recalculation' that LMP-dated ones often do.
Day-3 (cleavage stage): ~6–8 cells. Day-5 (blastocyst): ~70–100 cells, ready to implant. Most US IVF cycles now use day-5 because higher-quality embryos self-select by reaching blastocyst stage. The due date math accounts for the 2-day age difference.
Yes, based on the embryo's age at freezing. Frozen as a day-5 blastocyst? Count from transfer as if it were day-5 fresh. Freezing stops developmental time — once thawed and transferred, it picks up where it left off. Most US clinics do FET more often than fresh now.
Most IVF clinics do the first ultrasound at 6–7 weeks of pregnancy (~3–4 weeks post-transfer for a day-5 blastocyst). Yolk sac and possibly fetal pole + heartbeat are visible. Second ultrasound at 8–9 weeks usually confirms heartbeat. Most clinics graduate you to OB at 9–10 weeks.
Math matches the 266-day-from-conception rule used by US fertility clinics. Your RE may adjust by ±1 day based on early-ultrasound measurements. Not medical advice — confirm with your clinic. For complex cases (multiple embryos transferred, donor egg with unusual cycle synchronization), your clinic's date is authoritative.