How is the IVF due date calculated?

• 31 Jan, 2023
• IVF and Infertility
• infertility
• Medically Reviewed By: Dr. Nishi Singh
• Author: Prime IVF Centre

Finally, you have a positive pregnancy test result, probably after months of trying! Your next concern will most likely be, "What is my due date?" You are curious as to how long you will have to wait to experience this miracle. However, you can calculate your own due date if you want. 

Calculating your IVF due date is not the same as calculating your normal pregnancy due date. Read with us to learn about the method to calculate yours.

Methods to calculate the IVF due date

Pregnancy usually lasts 40 weeks. The first day of the last menstrual cycle is used to determine the due date for normal pregnancy because most women are unable to confirm when they ovulate. The due date is just an estimation because ovulation can vary from person to person. It usually occurs on the 14th day of a 28-day menstrual cycle.

However, women who have IVF can determine their due date more accurately because ovulation is detected during the IVF treatment cycle. You can calculate your due date using different methods, which are explained below:

Egg Retrieval Date

If you are starting a new IVF cycle, you may calculate your due date by calculating 266 days (38 weeks) from the date of the egg retrieval process. For example, if your eggs were collected on November 27, your due date would be August 20.

Embryo Transfer Date 

Using this approach, you will calculate 266 days (38 weeks) from the date the embryo transfers, then deduct the embryo's age. The age of the embryos is determined by whether you have a three-day or five-day embryo transfer. For example, if the embryo transfer is done on November 27, your due date would be August 17 if it was a 3-day transfer, as well as August 15 if it was a 5-day transfer.

Embryonic

The starting point is the time of embryo transfer into the womb. The embryo is placed in the patient's uterus on the third to the fifth day following the sperm-oocyte fusion, based on the embryo's development and the expecting mother's preparedness. The countdown starts on that day.

Obstetric 

This approach is used during a natural pregnancy or artificial insemination. According to it, the first day of the last menstrual period marks the beginning of gestation. The difference between embryonic and obstetric procedures is two weeks. However, with a normal cycle, the day of birth will be nearly the same.

Gynaecological

In this case, the time of the pregnancy is assessed by a gynaecological examination. Since the initial phase of embryonic development is the same for every woman, this calculation process is only effective until the end of the first trimester.

Ultrasound

This investigation is important for all expecting mothers, regardless of whether they became pregnant through natural means or through in-vitro fertilisation. The strategy calls for three tests: at 29-31, 18-21, and 11-14 weeks. However, with IVF, the number of examinations may increase. The doctor determines the exact date of the ultrasound examination.

IVF due date: How accurate is it?

Your IVF due date is an estimation, similar to the normal pregnancy due dates. Routine ultrasounds will be performed during your pregnancy to check the health of your developing foetus. The change in the development and size of the baby can result in a change of due dates. 

It is suggested that individuals use their due date as a general guide for predicting the approximate time of delivery. Your doctor closely observes your health for signs of delivery and labour as your due date gets closer, so you can make preparations.

The significance of the due date

The calculation of the due date is essential because it allows us to observe the child's growth as well as the status of the woman's body throughout various trimesters. 

Determining your due date is essential for planning considerations. Knowing your estimated due date helps you plan to welcome your child. You will have time to prepare for the delivery and buy essentials for the baby.

Knowing your due date also helps you receive proper prenatal care. Prenatal screenings and prenatal vitamins should be taken at the appropriate times during foetal development. Your doctor will also assess the foetus's position and size during your pregnancy to make sure that it's growing appropriately.

Doctors often use the method of evaluating the level of chorionic gonadotropin in the early stages of pregnancy. The placenta starts to produce this substance 5-7 days following embryo transfer. However, in some cases, the level of hCG in a mother's body may vary significantly due to a range of causes. It can result in an inaccurate estimate when the due date is calculated. In the first three months of pregnancy, obstetric or embryonic techniques for calculating the pregnancy term are more accurate.

The due date is calculated using a gynaecological approach in the second trimester, in which the clinician evaluates how well the foetus and uterus fit within the specified parameters. For the most accurate calculations, it is advised to use many approaches at once. It is recommended that an ultrasound scan be performed near the end of the pregnancy to determine the due date.

Is due date earlier for twins?

Most people are aware that the more foetuses that develop in your uterus, the more likely it is that you will give birth prematurely. Twins are more likely to be born earlier than single foetuses. Triplets are likely to be delivered earlier than twins. Quadruplets are more likely to be born earlier than triplets.

In such cases, your medical provider may even provide you with two due dates: one standard and one quite earlier, with the reasoning that twins often deliver relatively early. This does not mean that your infants will be ready to face the world when they are born earlier; it just means that you should not be frightened if you start labour sooner.

Learn more

Calculating your IVF due date can indicate how far along you are in your gestation or pregnancy and what you can expect next. We recommend you connect with our fertility experts to learn more about IVF treatment and how to calculate the due date. To book your appointment, please contact our centre online or give us a call.

FAQ

1. How is the IVF due date calculated?

IVF due dates are calculated with precision since ovulation and embryo transfer dates are known. Typically, it involves calculating 266 days (or 38 weeks) from either the egg retrieval date or the embryo transfer date. Adjustments may be made if you know the embryo's age at transfer. Ultrasound scans can also be used for more accurate dating. For instance, if you had a 3-day embryo transfer on November 27, your due date would vary from that of a 5-day transfer on the same date.

2. How accurate is the IVF due date?

The IVF due date is a relatively accurate estimation, considering that the timing of key events is known with precision. However, just like natural pregnancies, certain factors can lead to adjustments in the due date as pregnancy progresses. The development and size of the baby, as well as other factors, may necessitate a change in the estimated due date. It's essential to use your due date as a general guide for preparing for the arrival of your child and to follow your doctor's guidance closely as the pregnancy progresses.

3. Why is knowing the due date important during pregnancy?

Knowing your due date is crucial during pregnancy for several reasons. It enables IVF specialist to monitor the growth of your baby and assess the health of both you and your child throughout the different trimesters. Additionally, it allows for proper planning, both in terms of preparing for the delivery and ensuring that you receive the appropriate prenatal care, screenings, and supplements at the right times during fetal development.

4. What factors can influence changes in the IVF due date during pregnancy?

The IVF due date can change during pregnancy due to factors such as variations in the baby's development and size. Additionally, differences in the timing of important events, like embryo transfer, can affect the due date. Routine ultrasounds and healthcare provider assessments help in monitoring these factors and making necessary adjustments to the due date if required.

5. How can I book an appointment with fertility experts at Prime IVF Centre?

To schedule an appointment with our fertility experts at Prime IVF Centre, you can contact us online, call our center, or visit our website for more information. We're here to guide you on your fertility journey and address any questions or concerns you may have. Please call us at (+91) 9026869869 to set up an appointment and begin your fertility journey with us.