If you’ve just found out that you are pregnant, the first thing you’d probably want to know is your due date. You can calculate your due date in the following two ways:

  1. Counting down 280 days or 40 weeks from the first day of your last normal menstrual period
  2. Counting down 266 days from the date of conception

Since many women don’t remember the exact date of conception, the first method of calculating the due date is the more popular option. The 280 day/40 week span translates into approximately 9 months, which is the average length of a normal pregnancy, give or take a few days or weeks.

The due date is medically referred to as EDC or expected date of confinement, and it can be determined even if you don’t know the exact date of your last period. In such a case, the due date is revealed via an early ultrasound, preferably in the early stages of pregnancy to obtain a more accurate EDC.

However, you should be aware that a majority of pregnancies don’t take place on the determined due date. Approximately 80% of births occur anywhere between 10 days before and 10 days after the EDC. These are full term pregnancies where deliveries take place between 38-42 weeks.

Since due dates are not etched in stone, many obstetricians or specialists prefer providing a monthly timeframe to expectant mothers, such as telling them their baby will be born in mid-February, early June, September-end, etc. This alleviates stress in the mother to some extent when the EDC closes in and still enables her to stay alert when the time is near.

There are times when some births do not ‘conform’ to the 38-42 week/full term pregnancy schedule and the baby is born much before this period. These are premature births, which account for 8-10% of all deliveries.

Early labor can surface due to any reason, but the following have been seen in numerous premature birth cases:

–        Thyroid problems in the expectant mother

–        Infections or high fever in the mother

–        Hypertension, kidney disease, or diabetes in the mother

–        Tobacco use during pregnancy

–        Multiple births

–        Abnormal shape of the uterus

–        Abruption of the placenta

Post term pregnancies or pregnancies that surpass the 42 week timeframe are rare, and no reason has been determined for this occurrence because it’s more often than not a case of some women miscalculating their due date. However, if the due date comes to pass in your case, you can consult your obstetrician or specialist about induced labor and gauge if it’s required as a precautionary measure.