IVF Estimated Due Date (EDD) Calculator
Use this calculator to estimate your due date based on your In Vitro Fertilization (IVF) procedure details. You can calculate your EDD using either your egg retrieval date or your embryo transfer date and embryo age.
Understanding Your IVF Estimated Due Date (EDD)
For couples undergoing In Vitro Fertilization (IVF), calculating an Estimated Due Date (EDD) is a bit different from natural conception. While a natural pregnancy EDD is typically based on the Last Menstrual Period (LMP), IVF provides more precise dates for fertilization and embryo development, allowing for a more accurate initial estimate.
What is IVF?
In Vitro Fertilization (IVF) is a complex series of procedures used to help with fertility or prevent genetic problems and assist with the conception of a child. During IVF, mature eggs are collected (retrieved) from ovaries and fertilized by sperm in a lab. The fertilized egg (embryo) is then transferred to a uterus.
Why is IVF EDD Calculation Different?
In a natural pregnancy, the EDD is often calculated by adding 280 days (40 weeks) to the first day of the last menstrual period (LMP). This method assumes ovulation and fertilization occur around day 14 of a 28-day cycle. However, with IVF, we know the exact date of egg retrieval (which is analogous to ovulation/fertilization) or the exact date of embryo transfer and the age of the embryo.
How is IVF EDD Calculated?
The standard length of a full-term pregnancy from fertilization is approximately 266 days (38 weeks). Our calculator uses this principle based on the specific IVF dates you provide:
1. Based on Egg Retrieval Date:
If you know your egg retrieval date, this date is considered the equivalent of ovulation or fertilization. Therefore, your EDD is calculated by adding 266 days (38 weeks) to your egg retrieval date.
EDD = Egg Retrieval Date + 266 days
2. Based on Embryo Transfer Date and Embryo Age:
This is often the most precise method for IVF pregnancies. The calculation accounts for the age of the embryo at the time of transfer:
- For a 3-day embryo transfer: The "fertilization equivalent" date is considered to be 3 days before your embryo transfer date. Your EDD is then calculated by adding 266 days to this "fertilization equivalent" date.
- For a 5-day blastocyst transfer: The "fertilization equivalent" date is considered to be 5 days before your embryo transfer date. Your EDD is then calculated by adding 266 days to this "fertilization equivalent" date.
The general formula is:
EDD = (Embryo Transfer Date - Embryo Age in days) + 266 days
Important Considerations:
- An Estimate, Not a Guarantee: Your EDD is an estimate. Only about 4% of babies are born exactly on their due date. Most babies arrive within a week or two before or after the EDD.
- Consult Your Doctor: Always discuss your EDD with your fertility specialist and obstetrician. They will use this initial estimate along with early ultrasound scans to confirm and potentially adjust your due date.
- Individual Variations: Factors such as embryo quality, maternal health, and individual biological variations can influence the actual birth date.
Using the Calculator:
Simply enter either your Egg Retrieval Date OR your Embryo Transfer Date along with the Embryo Age at Transfer. The calculator will prioritize the embryo transfer details if both sets of information are provided, as it often offers a more direct path to the EDD.