My pregnancy calendar

Elia' s easy-to-use pregnancy calendar lets you print out and view the weeks of your pregnancy, trimesters and key dates at a glance, as well as your due date, ultrasounds and postpartum preparations. Follow the progress of your unborn child week by week.

To do so, simply enter the date of your last periodthe average length of your menstrual cyclethe number ofchildren you have or haven't had. Our pregnancy calendar will give you an exact idea of the key dates in your pregnancy.

Pregnancy generally lasts 9 months for most women, 41 weeks of amenorrhea. Three intense trimesters with their share of surprises, transformations and expectations. Between the changes in your body and the evolution of your fetus, certain dates are important to know to ensure the proper development of your baby and medical care adapted to your needs and state of health.

Write them down now, or download your pregnancy calendar, so you always have them with you!

• The date of your last menstrual period, the date of conception or the date of transfer or insemination for those undergoing MAP;
• Your due date;
• 1st trimester ultrasound, 2nd trimester ultrasound and 3rd trimester ultrasound from your gynecologist;
• Administrative: pregnancy declaration, maternity registration, appointments with your midwife, calculation of your maternity leave.

When your gynecologist talks to you about your pregnancy, he or she will probably talk about trimesters, weeks of amenorrhea and weeks of pregnancy. This is the difference betweenfetal age andgestational age.

Weeks of pregnancy

Pregnancy weeks are used to refer to the actual age of the unborn baby. In effect, from the date of conception to today's date. The date of conception is defined at the time of the first ultrasound scan or earlier, when the woman knows her ovulation date and the date on which she and her partner had intercourse. The pregnancy table is also easier to calculate when the mother-to-be has undergone MAP.

Weeks of amenorrhea

Gestational age is calculated in weeks of amenorrhea. Pregnancy is calculated from the date of the last menstrual period to birth, between 38 and 42 weeks. In general, the start of pregnancy and the age of your fetus will be calculated two weeks after the start of your last menstrual period.

Calculating on the first day of menstruation

Calculating your pregnancy on the basis of the first day of your period will be reliable as long as you have a regular 28-day cycle. This is because ovulation and the start of your last period will be considered the first two weeks of pregnancy. This method is therefore not 100% reliable.

To calculate your due date with the first day of your last period, you need to add 280 days. This will give you a good estimate of your due date.

Naegele rule

This rule is one of the most widely used for calculating due dates. To calculate your pregnancy calendar, we take the date of the 1st day of your last period, the length of your cycle between 20 and 45 days and add 280! On average, a cycle lasts 28 days, with ovulation occurring 14 days after the start of the cycle. If your cycle is shorter, the due date will be estimated earlier; if your cycle is longer, the due date will be later.

Mittendorf and William rule

The Mittendorf and William rule is more exhaustive than the Naegele rule. In fact, we use it to create our pregnancy calendar algorithm and application. In fact, we'll be collecting more information, so the results will be more accurate. A study shows that mothers-to-be who are expecting their first child (primigravida) have a longer pregnancy. The average is 288 days, compared with 283 days for those who have already had a first child (multiparous).

Our calendar will therefore be calculated by adding days of gestation to the Naegele rule.

• For primigravidas: 1st day of last menstrual period - 3 months + 15 days. That's 8 extra days;
• For multiparous females: 1st day of last menstrual period - 3 months + 10 days and 3 extra days;
• This adds 8 days for primigravida and 3 days for multipara, compared with the Naegele rule.

Parikh's rule

If you have an irregular cycle, as in the case of women with polycystic ovary syndrome (PCOS), for example, the Parikh formula will be used. Indeed, the Naegele formula could give an erroneous result. The formula is: day of last period + 9 months - 21 days + length of previous cycles.

Wood's rule

This formula takes into account the length of your usual menstrual cycles and the number of pregnancies you've already had and brought to term.

To begin, calculate your due date (DPA):

• For primigravida: 1st day of last menstrual period + 1 year - 2 months and two weeks;
• For multiparous women: 1st day of last menstrual period + year - 2 months and 2.5 weeks.

Then use the due date you have obtained and adapt it to the length of your cycle:

• For women with cycles longer than 28 days DPA + (actual cycle length - 28 days) = DPA ;
• For women with 28-day cycles: WFA - (28 days - actual cycle length) = WFA.

Calculating from the date of conception

Even if you know the date of your last sexual intercourse, the date of conception is rarely known, as spermatozoa have a maximum lifespan of 5 days and a woman's body ovulates 24 hours after being released from the ovary.

Calculating with ultrasound

Gynecologists or midwives will perform a dating ultrasound to get an accurate estimate of the baby's age based on its development. In general, a dating ultrasound is performed between the 11th and 13th week of amenorrhea, when menstruation is absent.

Calculating with the transfer or insemination date - PMA

If you are undergoing MAP treatment, particularly IVF, the date of conception is very easy to calculate, as it corresponds to the time of embryo transfer. This corresponds to the age of the embryo or the date of ovulation.