Pregnancy & Due Date
3 mins read

Pregnancy & Due Date

When you announce your pregnancy to the world, the first thing most people want to know is, “When are you due?” In fact, if you just found out that you are pregnant, this question may be at the forefront of your mind as well. Learn how to calculate your due date and what that all-important date really means.

Pregnancy & Due Date

True Length of Pregnancy

While we generally think of humans as having a nine-month gestation, it is really more accurate to say that pregnancy continues for 40 weeks. To add even more confusion into the mix, two of those weeks are actually prior to conception. This is because the length of a pregnancy is calculated from the first day of a woman’s last period. Typically, this is about two weeks before conception takes place, although every woman’s cycle is different.

What a Due Date Means

At the library, a due date is the last day to return your books before incurring any fines. Fortunately, a due date during pregnancy isn’t quite so rigid. Instead, your due date, or estimated due date (EDD) is simply a day in the middle of the range in which your baby will likely be born. A pregnancy is considered to be full term between week 37 and week 42 of gestation. Giving birth at any time during this range is generally considered to be safe and healthy for both mother and baby.

How to Calculate the Due Date

There is no shortage of online calculators to do the math for you, but calculating your due date is surprisingly simple. Using the first day of your last period, simply subtract three months and add seven days. For example, if the first day of your period was May 15, your EDD will be February 22. While this is the traditional way to calculate the due dates, some practitioners now simply add 40 weeks to the first day of your last period.

Other Ways to Determine Due Date

Every woman’s cycle is different. As a result, due dates aren’t a one-size-fits-all kind of calculation. If you have irregular periods or simply cannot remember the first day of your last period, your obstetrician or midwife can estimate your due date by measuring the size of your uterus, identifying the baby’s heart beat using a Doppler, or by performing an ultrasound examination. While these methods are not as precise as calculating from your last period, they can narrow down a due date to within two weeks.

Significance of the Due Date

While it would be nice to know exactly when your baby is coming, most babies work on their own timetable. For that reason, it is not surprising that fewer than 5 percent of women actually deliver on their due dates. Nevertheless, your due date provides you will an approximate time frame and gives your health care provider a basis for your prenatal care schedule. And though you may feel like you’ll be pregnant forever, the good news is that more than 90 percent of women deliver within two weeks of their due date.

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