Gestational age

Jump to navigation Jump to search

Template:Birth weight

WikiDoc Resources for Gestational age


Most recent articles on Gestational age

Most cited articles on Gestational age

Review articles on Gestational age

Articles on Gestational age in N Eng J Med, Lancet, BMJ


Powerpoint slides on Gestational age

Images of Gestational age

Photos of Gestational age

Podcasts & MP3s on Gestational age

Videos on Gestational age

Evidence Based Medicine

Cochrane Collaboration on Gestational age

Bandolier on Gestational age

TRIP on Gestational age

Clinical Trials

Ongoing Trials on Gestational age at Clinical

Trial results on Gestational age

Clinical Trials on Gestational age at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Gestational age

NICE Guidance on Gestational age


FDA on Gestational age

CDC on Gestational age


Books on Gestational age


Gestational age in the news

Be alerted to news on Gestational age

News trends on Gestational age


Blogs on Gestational age


Definitions of Gestational age

Patient Resources / Community

Patient resources on Gestational age

Discussion groups on Gestational age

Patient Handouts on Gestational age

Directions to Hospitals Treating Gestational age

Risk calculators and risk factors for Gestational age

Healthcare Provider Resources

Symptoms of Gestational age

Causes & Risk Factors for Gestational age

Diagnostic studies for Gestational age

Treatment of Gestational age

Continuing Medical Education (CME)

CME Programs on Gestational age


Gestational age en Espanol

Gestational age en Francais


Gestational age in the Marketplace

Patents on Gestational age

Experimental / Informatics

List of terms related to Gestational age

Gestational age is usually considered to be the age of an embryo or fetus (or newborn infant) from the first day of the woman's last menstrual period (LMP).[1] [2] This standard system of counting the progression of pregnancy starts approximately two weeks before fertilization takes place; it does not in itself constitute the beginning of pregnancy.[3] There is some controversy over the beginning of pregnancy, and alternative counting systems have been suggested.[3]

The gestational age should not be confused with the fertilization age (also called conceptional age or developmental age) of an embryo or fetus; the fertilization age is always counted from fertilization, and the gestational age is usually greater by about two weeks.

A full-term human pregnancy is considered to be 40 weeks (280 days), though pregnancy lengths between 38 and 42 weeks are considered normal. A fetus born prior to the 37th week of gestation is considered premature and faces increased risk of morbidity and mortality.

The events of prenatal development usually occur at known gestational ages. The gestational timing of a toxin exposure or infection can be used to predict the potential consequences to the fetus.

Calculations of gestational age from LMP are sometimes incorrect due to normal varation from the average ovulation date. The gestational age of an individual infant can be more accurately estimated from:

  1. The mother's knowledge of the date of sexual intercourse.
  2. The mother's knowledge of fertility signs related to ovulation. The needed observations are normally made by mothers who use fertility awareness methods to get pregnant.
  3. Examination of the newborn infant. In the twentieth century, doctors (especially pediatricians) were trained to recognize the physical changes occurring to the fetus in the latter half of pregnancy so that a maturational age could be estimated.
  4. An obstetric ultrasound ("dating scan", in the UK routinely offered around 12 weeks) during the pregnancy, whereby sizes of certain fetal body parts are measured.

The fertilization age of children conceived by in vitro fertilization is known to the hour.

See also


  1. John Goldenring, ed. (November 2004). "MedlinePlus Medical Encyclopedia: Gestational age". A.D.A.M., Inc. Retrieved 2007-01-28. (distinguishing between "calendar gestational age" and "developmental gestational age").
  2. Anika Rahman, Laura Katzive and Stanley K. Henshaw. A Global Review of Laws on Induced Abortion, 1985-1997, International Family Planning Perspectives (Volume 24, Number 2, June 1998): there is "no uniform method of calculating gestational age."
  3. 3.0 3.1 Engle W, American Academy of Pediatrics Committee on Fetus and Newborn (2004). "Age terminology during the perinatal period". Pediatrics. 114 (5): 1362–4. PMID 15520122. Retrieved 2007-01-28.

External links


Template:WH Template:WikiDoc Sources