Shephard, Bruce D. Diplomates, American College of Obstetricians and Gynecologists, Tampa Obstetrics and Gynecology Associates, Tampa, Florida.
Last reviewed:March 2018
Show previous versions
- Establishment of pregnancy
- Embryonic development
- Prenatal care
- Safety and postnatal care
- Termination of pregnancy
- Links to Primary Literature
- Additional Readings
The period during which a developing fetus is carried within the uterus. In humans, pregnancy averages 266 days (38 weeks) from conception to childbirth. Traditionally, pregnancy duration is counted from the woman's last menstrual period, which adds roughly 2 weeks to the gestational age. This is how physicians arrive at a pregnancy length of 40 weeks (280 days). The 9 months of human pregnancy are typically divided into three periods (trimesters) of 3 months each (Fig. 1). See also: Animal reproduction; Gestation period; Uterus
The content above is only an excerpt.
for your institution. Subscribe
To learn more about subscribing to AccessScience, or to request a no-risk trial of this award-winning scientific reference for your institution, fill in your information and a member of our Sales Team will contact you as soon as possible.
to your librarian. Recommend
Let your librarian know about the award-winning gateway to the most trustworthy and accurate scientific information.
AccessScience provides the most accurate and trustworthy scientific information available.
Recognized as an award-winning gateway to scientific knowledge, AccessScience is an amazing online resource that contains high-quality reference material written specifically for students. Contributors include more than 9000 highly qualified scientists and 43 Nobel Prize winners.
MORE THAN 8500 articles and Research Reviews covering all major scientific disciplines and encompassing the McGraw-Hill Encyclopedia of Science & Technology and McGraw-Hill Yearbook of Science & Technology
115,000-PLUS definitions from the McGraw-Hill Dictionary of Scientific and Technical Terms
3000 biographies of notable scientific figures
MORE THAN 19,000 downloadable images and animations illustrating key topics
ENGAGING VIDEOS highlighting the life and work of award-winning scientists
SUGGESTIONS FOR FURTHER STUDY and additional readings to guide students to deeper understanding and research
LINKS TO CITABLE LITERATURE help students expand their knowledge using primary sources of information