IVF Due Date Calculator

An IVF due date is estimated from a precisely known treatment event rather than from the first day of a recalled menstrual period. Fertilization and embryo age are documented during assisted reproduction, so the dating calculation can account for the developmental days that have already passed before transfer. This calculator supports a day 3 embryo transfer, a day 5 blastocyst transfer, and an egg retrieval or fertilization date. A typical pregnancy due date represents 280 days, or 40 weeks, from the first day of the last menstrual period. Conception is conventionally placed about 14 days after that gestational starting point, making the interval from fertilization to due date about 266 days. For egg retrieval, the calculator adds 266 days. For a day 3 transfer, three embryonic days have already elapsed, so it adds 263 days. For a day 5 blastocyst transfer, it adds 261 days. The equivalent gestational start shown with the result is useful for understanding standard pregnancy-week labels. The estimate is not a guarantee of the delivery date. Only a small proportion of babies arrive on the exact estimated date, and a normal delivery window extends before and after it. Your fertility clinic may date the pregnancy using its own recorded fertilization time, frozen-transfer protocol, donor cycle records, or ultrasound findings. Early ultrasound can confirm growth and may identify clinically meaningful discrepancies, but clinicians generally avoid changing dates without a clear reason when IVF timing is reliable. Use the procedure date found in the clinic record rather than the date of a positive pregnancy test. For frozen embryo transfer, use the actual transfer date and choose the embryo age at transfer. A day 6 blastocyst may require clinic-specific dating; ask the care team which convention they use. Do not treat the calculated gestational start as an actual menstrual date, because suppression, stimulation, retrieval, and transfer protocols often alter the natural cycle. Pregnancy milestones, screening windows, and decisions about delivery should be scheduled with an obstetric or fertility professional. This calculator is intended for planning and education, not diagnosis. Contact the care team for bleeding, severe pain, faintness, breathing difficulty, or other urgent concerns. Keep the clinic’s official due date in the medical record, since that date should guide prenatal testing and treatment.