IVF Due Date Calculator

Please read our disclaimer before using the IVF Due Date Calculator below.

Modern assisted reproduction technologies have helped countless couples experience parenthood.

Most couples undergoing IVF procedures are eagerly awaiting their due date to meet their child finally. Due date calculators allow you to determine the baby’s date of birth.

With the correct determination of the timing of pregnancy, doctors and the expectant mother can know in advance the approximate date of the onset of labor. This allows them to prepare for this process, identify possible complications and choose the appropriate delivery method.

That is why it is so necessary for pregnant women to regularly visit a doctor as part of an IVF program and calculate their due dates.

How Can You Calculate Your IVF Due Date?

Naegele’s Rule Calculator and the Mathematical Method

First, let’s briefly discuss how the due date is calculated for natural conception and then compare it to pregnancy using IVF.

The average range of duration of pregnancy is approximately 36 to 42 weeks. The average duration of pregnancy is 40 weeks or 280 days.

In the case of natural conception, treatment with fertility drugs, or IUI (intrauterine insemination), due date calculations are based on the first day of the last menstrual period.

Due dates can be calculated by the following:

Naegele’s Rule

This method works best when the patient has a regular (28-day) menstrual cycle without significant fluctuations.

Three months are subtracted from the day of the last period, and 1 year and 7 days are added.

Mathematical method

IVF Due Date Calculator - mathematical method

IVF Due Date Calculator – mathematical method

Just by adding the average period of pregnancy (280 days) to the start date of the last menstrual period, you can get the estimated date of birth.

Methods for calculating due date in IVF

On the other hand, in the case of IVF, everything is much easier since we know the exact date of conception, as this is done artificially in the lab. Therefore, tracking the day of ovulation is not needed like it is for a natural pregnancy.

Due date calculation is possible by adding 266 days to the egg retrieval or embryo transfer date.

Let’s review the methods for calculating due dates according to the types of IVF:

1. IVF with own eggs

In this case, where eggs are retrieved from the mother rather than a donor and then fertilized in the lab, 266 (38 weeks) days are added.

Formula: Egg retrieval date + 266 days = Due date

2. Day 3 embryo transfer or day 3 FET (Frozen Embryo Transfer)

An embryo, consisting of several cells, is transferred 3 days after fertilization. Since the embryo is considered 3 days “old” already, 263 days are added to the IVF transfer date instead of 266.

Formula: Transfer date + 263 or Transfer date + 266 – 3 = Due date

3. Day 5 embryo/blastocyst transfer or day 5 FET

For this method, the embryo is transferred 5 days after fertilization. Since the embryo is already considered 5 days “old” already, 261 days are added to the transfer date.

Formula: Transfer date + 261 or Transfer date + 266 – 5 = Due date

4. IVF with fresh donor egg cycle

In this instance, where the donor’s eggs are fertilized, 266 days are added.

Formula: Egg retrieval date + 266 days = Due date

5. Fresh donor embryo cycle

It consists of the retrieval and fertilization of donor eggs. As this is usually done on the same day, 266 days (38 weeks) are added.

Formula: Egg retrieval date + 266 days = Due date

Multiple Gestations

In multiple gestations (twins, triples, etc.), the IVF due date formula changes since a more significant number of gestations raise the risk for a shorter pregnancy. For this, doctors need to do additional tests, usually an ultrasound.

Confidence of IVF Due Date Calculator

Although IVF due date estimates are typically more accurate than pregnancies following natural conception, the calculator alone does not guarantee absolute accuracy.

In any case, a detailed medical evaluation is required to confirm the probable due date.

The actual due date is based on factors such as the mother’s and fetus’s health, the number of fetuses, the mother’s hormonal balance, and fetal positions. Therefore, the IVF due date calculation is an estimate, likely to be within +/- 2 weeks accuracy. Only about 5% of babies arrive on their estimated due date.

Estimating a baby’s due date with the help of an IVF due date calculator aids the mother herself in planning her pregnancy.

Every pregnancy is individual and unique in its way. Thus, the prognosis is not the same for every IVF pregnancy due date. That’s why you need constant communication with your physicians, fertility doctor, and midwife during pregnancy.


By using the grantsformedical.com’s calculator, documentation and/or any software found therein, the User agrees to abide by grantsformedical.com’s Terms and Conditions.

This calculator is for informational purposes only and should be used only for estimations. Differences in calculations can have enormous clinical consequences. These tools do not give professional or healthcare advice. This information is not intended to replace clinical judgment or guide individual patient care in any manner.

Your reliance upon information and content obtained by you at or through this website is solely at your own risk. Neither Five Buttons, LLC nor grantsformedical.com shall be liable for any special, consequential, damage or injury (including death) to you, other persons or exemplary damages resulting in whole or part from any User’s use of or reliance upon this calculator and the information contained within.

grantsformedical.com and the system’s authors, developers and distributors assume no responsibility for any erroneous results due to defects in the system. Access to and use of the grantsformedical.com is provided without warranty of merchantability or fitness for any particular purpose or any other warranty, express or implied.

See Also

How Much Does IVF Cost?

Grants for IVF

Loans for IVF

I am an experienced medical content writer, translator, and resident physician.

Franco Cuevas is a physician who graduated from the National University of Córdoba, Argentina. He practices general medicine in the Emergency Department at Sanatorio de la Cañada, Córdoba. His focus is on writing medical content to improve physicians' access to relevant medical information for daily practice. He has participated in some research projects and has a special joy in teaching and writing about medical concepts.

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