How to calculate the expected due date

It is often said that a pregnancy lasts 9 months, yet it is generally calculated in the number of weeks. 40 weeks, or 280 days to be precise. In the end, it is relatively the same, within a few days, but it is more accurate to calculate the expected delivery date this way, in order to be able to plan the various appointments at the right time and verify that the pregnancy is progressing normally at each important stage.

‍

How long does a pregnancy actually last?

You should know that the duration of a pregnancy varies from one woman to another, and that according to studies, a normal pregnancy would actually be a little longer than 40 weeks. In the majority, women would give birth spontaneously between 40 weeks 3 days (40 3/7) and 41 weeks 2 days (41 2/7). Some may even exceed more, however, doctors usually suggest inducing labor during the 41^E week, because the risks of continuing the pregnancy would be greater than those of causing delivery.

‍

How to calculate the expected due date?

Pregnancy is calculated in weeks of amenorrhea, which is the number of weeks without menstruation. Health professionals will therefore Calculate the expected due date based on the date of day 1 of the last menstrual period, even if you were not yet pregnant.

It is also possible to calculate the expected date of delivery based on the date of conception, when for example, it is an insemination or when the woman does not remember the date of her last menstrual period, but she does know her date of ovulation or conception.

In the case of IVF, the expected date of delivery will then be calculated according to the date of implantation taking into account the age of the embryos.

‍

The dating ultrasound

A woman may not know when she had her last menstrual period or when she had her last menstrual period. It is then recommended to do a dating ultrasound around 9-10 weeks approximately, in order to validate the stage of the pregnancy and determine an expected delivery date. An ultrasound is also recommended for women who have irregular cycles (long or short). For other women, dating is done during the nuchal translucency ultrasound around 12-13 gestational weeks.

For make an appointment for a blood pregnancy test (confirm a pregnancy) or for a dating ultrasound (determine the expected date of delivery), do not hesitate to call us. Our team will be happy to talk to you!

‍

Reference:

https://naitreetgrandir.com/fr/grossesse/trimestre1/duree-grossesse/#:~:text=Lors%20du%20suivi%20de%20grossesse,premi%C3%A8re%20journ%C3%A9e%20des%20derni%C3%A8res%20menstruations