Search Encyclopedia:    
List of Topics Print This Page
 

Gestational age


Definition:

Gestation is the period of time between conception and birth. During this time, the baby grows and develops inside the mother's womb.

Gestational age is the common term used during pregnancy to describe how far along the pregnancy is. It is measured in weeks, from the first day of the woman's last menstrual cycle to the current date. A normal pregnancy can range from 38 to 42 weeks.

Infants born before 37 weeks are considered premature. Infants born after 42 weeks are considered postmature.

Alternative Names:

Fetal age; Gestation

Information:

Gestational age can be determined before or after birth.

Before birth, your doctor will use ultrasound to measure the size of the baby's head, abdomen, and thigh bone. This helps determine how well the baby is growing in the womb.

After birth, gestational age can be measured by looking at the baby's weight, length, head circumference, vital signs, reflexes, muscle tone, posture, and the condition of the skin and hair. The baby's developmental gestational age may not be the same as the calendar age. For example, an infant born at 36 weeks may actually have a developmental gestational age of 38 weeks. This baby may be more like a full-term infant than a baby born prematurely.

Determining a baby’s gestational age is important. It gives your doctor information that help set the baby’s medical treatment plan.

References:

Benson CB, Doubilet PM. Fetal measurements: normal and abnormal fetal growth. In: Rumack CM, Wilson SR, Charboneau JM, Levine DL. Diagnostic Ultrasound. 4th ed. Philadelphia, PA: Elsevier Mosby; 2010:chap 42.


Review Date: 12/4/2013
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright 2002 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

   View History
  Gestational age

Related Links
Request an Appointment Online or call
1-800-789-PENN (7366)
List physicians for this condition
   
   

 

About UPHS   Contact Us   Site Map   Privacy Statement   Legal Disclaimer   Terms of Use

The University of Pennsylvania Health System, Philadelphia, PA 1-800-789-PENN © 2014, The Trustees of the University of Pennsylvania