Due Dates

“What is my baby’s due date” and “How Far along am I,” and “How much does my baby weigh?”

Your OB will tell you your “due date” or estimated date of confinement (EDC) on your first OB visit. To calculate your due date is a simple matter (Naegele’s Rule): Subtract 3 months from your last menstrual period (LMP) and add 1 week (add a year if your LMP was March 25th or later).

For example: Your LMP is June 6, 2014 then your due date would be March 13, 2015.

In another way of figuring: 6/6/2014 minus 3 months equals 3/6/2014 plus one week makes 3/13/2014 then add one year equals 3/13/2015

06/06/2014
Minus 3 months
03/06/2014
Add one year
03/06/2015
Add one week
03/13/2015

“Due dates” rarely change. Due dates are the most reliable when calculated in the first trimester. If you want to monitor your baby, “there is an App for that!” The “Pregnancy Wheel” and other similar Apps (baby developmental steps, what is my baby doing now, etc.) are available for download for Smartphones and on your computer. The Apps will also tell you all the information you desire on a weekly basis. In the illustration provided, there is a Pregnancy Wheel that is helpful when the LMP is not certain: just input the weeks calculated by ultrasound (or fundal height) on the wheel and the date of conception and EDC is shown.