IVF Due Date Calculator - Ferty9 Fertility Center

What is an IVF Pregnancy Due Date?

An IVF pregnancy due date is an estimated date of birth calculated based on the precise timeline of your IVF treatment. Unlike a natural pregnancy, where the exact date of conception can be uncertain, IVF provides exact milestones. We know the precise date the eggs were retrieved and fertilised, or the exact date the embryo was transferred to the uterus. This knowledge makes your IVF due to date one of the most accurate estimates possible.

How Do You Calculate Your Due Date with IVF?

Doctors use a couple of straightforward, reliable methods based on your specific IVF procedure. The goal is to calculate a date that is 40 weeks (280 days) from the start of a “standard” menstrual cycle.

Method 1: Based on Egg Retrieval Date

This is a very common method. The day of your egg retrieval is considered “Day 14” of a typical cycle. Your due date is calculated by simply adding 266 days (38 weeks) to your egg retrieval date.

Formula: Egg Retrieval Date + 266 Days = Your Due Date

Method 2: Based on Embryo Transfer Date

This is the most widely used method. The calculation depends on the age of the embryo when it was transferred.

For a 3-Day Embryo Transfer: Your due date is calculated by adding 263 days to your transfer date.
- Formula: 3-Day Transfer Date + 263 Days = Your Due Date
For a 5-Day Embryo (Blastocyst) Transfer: Your due date is calculated by adding 261 days to your transfer date.
- Formula:5-Day Transfer Date + 261 Days = Your Due Date

What Other Ways Can You Calculate Your IVF Due Date?

While the methods above are most accurate, your doctor may also use these for confirmation:

Hypothetical Last Menstrual Period (LMP): Your doctor might calculate a “mock” LMP date by subtracting 14 days from your egg retrieval date. This helps align your IVF pregnancy with standard obstetric charts and calculators.
Ultrasound Scans: An early ultrasound, usually done between 8 to 12 weeks, is the best way to confirm your due date. The sonographer will measure the baby’s length (Crown-Rump Length or CRL), which is a very accurate indicator of gestational age in the first trimester.

How Accurate Are IVF Due Dates?

IVF due dates are considered highly accurate. The main reason is the elimination of guesswork. In a natural pregnancy, uncertainty about the exact day of ovulation and fertilization can lead to a due date that might be off by several days. With IVF, these dates are known precisely, giving you and your doctor a reliable timeline from day one.