IVF Due Date Formula:
From: | To: |
The IVF due date calculation accounts for the age of the embryo at transfer, providing a more accurate estimate than traditional pregnancy dating methods. It's based on the concept that pregnancy duration is 266 days from conception (38 weeks).
The calculator uses the IVF due date formula:
Where:
Explanation: The calculation adjusts for the embryo's development time in the lab before transfer.
Details: Accurate due dating is crucial for proper prenatal care timing, growth monitoring, and scheduling important tests and procedures.
Tips: Enter the exact embryo transfer date and the embryo's age in days (typically 3 for day-3 embryos or 5 for day-5 blastocysts).
Q1: Why 266 days instead of 280?
A: 280 days (40 weeks) is calculated from the last menstrual period (LMP). IVF dating uses actual conception time (266 days/38 weeks from conception).
Q2: What's the difference for day 3 vs day 5 embryos?
A: Day 5 embryos are 2 days "older" in development terms, so the due date will be 2 days earlier than for a day 3 embryo transferred on the same date.
Q3: Does this work for frozen embryo transfers?
A: Yes, the same calculation applies whether the embryo was fresh or frozen at transfer.
Q4: How accurate is this calculation?
A: It's the most accurate method for IVF pregnancies, though individual variations in pregnancy length still occur.
Q5: Should I adjust for my long/short menstrual cycles?
A: No, IVF dating doesn't use menstrual cycle information since we know the exact conception timeline.