Best IVF Due Date Calculator – FET And Pregnancy

You can use BellyBelly’s IVF due date calculator to work out your due date. Simply put in your IVF treatment type (your own egg or donor, fresh or FET), type of pregnancy (single, twins or triplets) and transfer date, and the calculator will work its magic and calculate your estimated due date.

What is an IVF due date calculator?

An IVF (in vitro fertilization) -specific due date calculator is necessary to make sure you receive a more accurate result. Most due date calculators rely on the date of the first day of the mother-to-be’s last period. These calculators work on date estimation, by assuming all women have a 28-day menstrual cycle and that ovulation occurs on day 14. Cycle length varies hugely between women (and even month to month for some women), so most women don’t know their conception date when carrying a natural pregnancy.

Even if you were intimate on one day that month, you wouldn’t know when conception occurred because sperm can lie in wait for up to five days, waiting for the ovaries to release an egg during ovulation. Without knowing precisely when ovulation occurred, it’s impossible to determine an accurate due date with a due date calculator. The advantage of an IVF conception is that you know the egg retrieval and embryo transfer date, which allows you to get a more accurate due date.

Why is an IVF due date calculator important?

A pregnancy due date calculator IVF setting is essential because it performs a due date calculation based on your embryo transfer date. The IVF journey can be emotionally and physically arduous, and having an estimated due date allows you to start loosely planning for (and, most importantly, getting excited for) your baby’s arrival.

With an IVF pregnancy, you have the benefit of knowing exactly when your conception date occurred. IVF takes some of the guesswork out of calculating your due date. An IVF due date calculator estimates your due date based on more accurate information, thanks to the IVF process. Using an IVF date calculator helps get a more accurate date, although it will only provide estimations of the due date because gestational time isn’t an exact science.

What is an IVF due date calculator for FET?

The benefit of using an IVF-specific calculator is that it considers all the factors affecting your embryo transfer. An IVF due date calculator for FET (Frozen Embryo Transfer) considers the embryo’s age and date of transfer when determining your estimated due date.

How accurate is an IVF due date calculator?

Although the IVF process allows a due date calculator to determine your pregnancy due date more accurately, it’s essential to remember that it only provides an estimated due date. Pregnancy doesn’t last for a set number of days; the length of pregnancy varies. Pregnancies usually last about 40 weeks, although full term means anytime between 37 and 42 weeks of gestation. That means there’s a big window on either side of your estimated due date where premature birth may occur.

An IVF due date calculator can give you an estimated due date for your IVF pregnancy. Towards the end of your first trimester, you will have a dating scan (a 12-week ultrasound scan) to give a more accurate due date. During the scan, your sonographer will measure your baby and use this information to provide a more accurate due date.

Essential guide to using a due date calculator

Using our IVF due date calculator couldn’t be easier. All you need to do is put in what type of fertility treatment you had, what type of pregnancy you’re having (one baby, twins or triplets) and your transfer date, and it will calculate your due date.

IVF due date calculator – for one baby, twins or triplets

BellyBelly’s IVF due date calculator can calculate IVF baby due dates for single pregnancies, twins and triplets. Twins and triplet pregnancies tend to be shorter than singleton pregnancies, and our calculator takes this into account.

IVF is traditionally associated with an increased chance of having multiples. A 2024 study published in the European Journal of Obstetrics, Gynecology and Reproductive Biology found that the number of multiple births from IVF was 23.8% in 2007-2008, and that this number had decreased to 8.4% by 2021-2022. The reduced number of multiple births can largely be attributed to changes in IVF practices, such as reducing the number of multiple embryo transfers.

Frequently Asked Questions

What is IVF?

IVF (in vitro fertilisation) is a fertility treatment whereby an egg is removed from the ovaries and fertilised with sperm in a lab. The fertilised egg (embryo) is placed into the woman’s uterus.

How successful is IVF?

IVF success depends on various factors, including age, ovarian reserve and sperm quality. According to the Human Fertilisation and Embryology Authority, average IVF success rates with fresh embryo transfers were 31% in 2022. The highest success rates, at 42%, were among those aged 18-34. For those aged 40-42, IVF pregnancy rates were 16%. Those aged 43-44 had a 9% chance of pregnancy.

What is FET?

During an IVF cycle, it’s typical to end up with more than one embryo. Usually, only one embryo is transferred into the uterus, and any remaining embryos will be frozen for future use. FET means frozen embryo transfer, where a frozen embryo is thawed and transferred into the uterus. Sometimes, fertility doctors will recommend freezing all of the embryos to boost your chances of success.

What is the difference between fresh and frozen transfer?

A fresh donor embryo cycle transfer occurs days after egg retrieval, when the fertilised egg is placed into your uterus in the hopes of achieving a pregnancy. If you are lucky enough to have some extra embryos, they will be frozen to preserve the fertilised egg for future use. During a frozen embryo transfer, an embryo is thawed and placed in your uterus.

In some cases, you might have a freeze-all cycle, where all embryos are frozen for a number of weeks to give your infertility specialist a chance to increase the lining of your uterus and give you the best chance of a successful pregnancy.

A 2021 study published in JBRA Assisted Reproduction found that using frozen embryos increased the chance of pregnancy success. You should speak to your fertility doctor to find out whether this is a recommended option for you.

When are frozen embryos transferred?

Most embryo transfers with fresh embryos take place on day 3. Leaving the embryos till day 5 means they are further developed and have a higher chance of success. However, not all embryos will make it to day 5, which is why some doctors prefer to transfer on day 3, to give the embryo a fighting chance in the optimal conditions in the woman’s uterus, rather than in the lab.

On day 5, embryos reach the blastocyst stage, improving the chance of a successful pregnancy. Some embryos might not reach the blastocyst stage until day 6 or 7. Fertility technicians monitor your embryos carefully to determine the best time to transfer, so as to give you the best chance of success.