ALERT

Access info on COVID tests, vaccines, visitor policy, hospitalization data, and FAQs.
toggle mobile menu Menu
toggle search menu

Site Navigation

Supplemental

Menu

Gestational Age

Top of the page

Gestational Age

Gestational age is the number of weeks and days a fetus has developed since the beginning of the pregnancy, or gestation. A pregnancy is formally considered as beginning on the first day of the mother's last menstrual period (LMP).

An infant born before 37 completed weeks' gestation is considered premature. A premature infant is often referred to in terms of gestational age (a "30-weeker"), which implies a particular point of development at birth. After a premature infant is born, the gestational age is also referred to as the infant's postconceptional age. This figure is useful for estimating an infant's growth and development until some time around the due date (40 weeks).

Gestational age is also estimated by using ultrasound measurements of the fetus combined with the dates of first fetal heart tones and other developmental milestones. After the infant is born, there are a variety of characteristics that can be used to estimate the gestational age.

It is possible for gestational age to be inaccurate by up to 2 weeks, even with an accurate LMP date confirmed by other tests.

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. Healthwise is a URAC accredited health web site content provider. Privacy Policy. How this information was developed to help you make better health decisions.

To learn more, visit Healthwise.org

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

Take Care, Someone Needs You.

You take care of others, so take care of yourself. Let us be your partner in health, whether you're recovering from an injury, checking in for your annual exam, or enjoying an online class.

Because when you take care of yourself, everyone around you benefits.

Connect with Us
Contact Us In Boise (208) 381-2222