What Your Due Date Does Not Mean

Monthly Calendar Circled Date
Photo © Dreamstime

The truth is that everyone wants to know what their due date is for their current pregnancy. It is probably one of the first things that a mother-to-be calculates and recalculates after a positive pregnancy test. I have also heard of moms knowing this date even before they pee on the stick. Once at their first prenatal visit, they confirm this date, maybe moving it slightly one way or the other. Then it’s there – your due date.

I think many women think they know what a due date is, but I want to focus on what a due date is not.

It Is Not Set in Stone

Sometimes there is a need to move your due date. This happens enough that it is important to talk a bit about when it should be moved. You should have your due date moved when there is credible evidence, like an early ultrasound that provides a date that is off by plus or minus ten days or ultrasounds between 12 and 20 weeks of pregnancy that indicate a difference of 14 days. Ultrasound data should not be used after 20 weeks to manipulate your due date.

It Is Not a Time Limit

Unlike expiration dates on food, your due date is an estimate of when your baby will arrive. The truth is that the 40-week mark shows up three-fifths of the way into a five-week period that is when your baby is most likely to be born. Think of your due date as the peak of a bell curve, with babies coming spontaneously before and after that date.

Unless you have reached the end of the 42-week mark, or there are medical reasons, induction of labor is generally not recommended.

It is not an appointment.

This may break the hearts of many type A  moms, but statistically speaking only about 3-4% of all babies are actually born on their due dates. You cannot write your due date on your calendar and plan on the baby showing up on that day.

It does happen, but again, fairly unlikely.

It Is Not Something to Be Shared

This advice might sound odd, but hear me out. Thinking about your due date with flexibility built in is critical. This should start as soon as you learn you are pregnant. This includes how you share the information with your family and friends who may not know a thing about due dates, other than how to write them in your calendar.

Avoiding giving those close to you an exact date in early pregnancy can save you some heartache later in pregnancy. You give them a date, they write it in and then a week before, if not sooner, they start bugging you. And that can really drive you crazy at a time when you really need life to be more low key. Some doctors advise giving due months. An example is that if you’re due June 10th, you say you’re due in June. Due later in the month? Simply say late June, early July when you tell the family.

It Is Not Fudgeable

Your baby knows how long his or her gestation is in pregnancy. So if you are trying to induce labor early, because you’re “close enough” to your due date, your baby will suffer the consequences. Without a medical reason, you should never attempt to or allow an induction prior to 39 weeks, and even 40 is more preferable.

If you have questions about your due date or changes in your due date, be sure to ask your midwife or doctor about what is going and why the changes are being suggested or answer the questions you may have about when your baby will be born.


Baskett, Thomas F., & Nagele, Fritz. (2000). Naegele's rule: a reappraisal. BJOG: An International Journal of Obstetrics & Gynaecology, 107(11), 1433-1435. doi: 10.1111/j.1471-0528.2000.tb11661.x

Olesen, AW & Thomsen, SG. (2006). Prediction of delivery date by sonography in the first and second trimesters. Ultrasound Obstet Gynecol, 28(3), 292-297.

Taipale, P, & Hiilesmaa, V. (2001). Predicting delivery date by ultrasound and last menstrual period in early gestation. Obstet Gynecol, 97(2), 189-194.

Continue Reading