Decrease (-) Restore Default Increase (+)
Print    Email
Bookmark and Share

Health Information

Health Information

Health Information

Health Information - Definition

Search Health Information    Due Date

Due Date

A due date is an estimate of when a pregnant woman will have her baby. It is calculated by taking the first day of her last menstrual period (LMP), adding 7 days, and then counting backward 3 months; or by adding 40 weeks from the first day of the last menstrual period (for women with regular 28-day cycles).

For example, using the first method, if a pregnant woman's last period started on March 20, add 7 days to get March 27 and then subtract 3 months to get a due date of December 27. Using the second method, 40 weeks counted from March 20 is December 25.

The due date is only an estimate of when a woman will deliver. Most women do not give birth on their due date, but they do within 2 weeks before or after.

Last Revised: July 23, 2012

Author: Healthwise Staff

Medical Review: Sarah Marshall, MD - Family Medicine & Kirtly Jones, MD - Obstetrics and Gynecology

This information does not replace the advice of a doctor. Healthwise, Incorporated disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.

© 1995-2014 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.

© 2014 St. Mary's Health System   |  3700 Washington Avenue  |  Evansville, IN 47750  |  (812) 485-4000