IVF Due Date Calculator

Unlike natural conception where the last menstrual period (LMP) serves as the baseline, IVF pregnancies are dated using the precise age of the embryo and the date of either egg retrieval or embryo transfer. The standard human gestation period is modeled at 280 days (40 weeks) from the LMP. For a 3-day cleavage-stage transfer, you add 267 days to the transfer date. For a 5-day blastocyst transfer, you add 265 days. Alternatively, the formula accounts for the egg retrieval date by adding 14 days plus the remaining gestational period to arrive at the estimated due date (EDD).

Let us walk through a practical scenario for a patient undergoing an IVF cycle. Suppose you undergo a 5-day blastocyst frozen embryo transfer on June 1, 2024. Because a blastocyst is already 5 days old at transfer, the standard medical convention subtracts those 5 days from the full 266-day post-transfer gestation window to align with standard Naegele's rule adjustments, or more directly, you add 265 days to June 1, 2024. Adding 265 days to June 1 results in an estimated due date of February 21, 2025. From this due date, you can easily project your gestational age week by week.

To ensure the most accurate tracking of your pregnancy, always use the specific age of the embryo on the day of transfer rather than standard menstrual cycle estimates. Keep your initial early ultrasound dates in mind, as reproductive endocrinologists rely heavily on early crown-rump length measurements to confirm or slightly adjust the initial IVF-derived due date. Finally, remember that twin or triplet pregnancies often result in a shorter average gestation length, which your obstetrician will factor into your ultimate delivery plan.