Trimester

Content provided by Healthwise

Trimester

A normal pregnancy lasts about 40 weeks from conception to the birth of a baby. This time is roughly divided into 3 periods: the first trimester, from conception to about the 12th week of pregnancy; the second trimester, from about 13 to 27 weeks of pregnancy; and the third trimester, from about 28 weeks of pregnancy until birth.

Each trimester of pregnancy is marked by developmental changes in the fetus.

By the end of the first trimester (about week 12 of pregnancy) the fetus has a recognizable human form.
By the end of the second trimester (about week 27 of pregnancy), all the vital organs of the fetus have developed. Also, the mother begins to feel the fetus begin to move (quickening), usually starting between weeks 16 and 20.
During the third trimester (about week 28 until birth), the fetus's size increases and organs mature.

Credits

Print Email SHARE

Author	Jeannette Curtis
Author	Caroline Rea, RN, BS, MS
Editor	Kathleen M. Ariss, MS
Editor	Susan Van Houten, RN, BSN, MBA
Associate Editor	Tracy Landauer
Associate Editor	Pat Truman, MATC
Primary Medical Reviewer	Patrice Burgess, MD - Family Medicine
Primary Medical Reviewer	Adam Husney, MD - Family Medicine
Primary Medical Reviewer	Kathleen Romito, MD - Family Medicine
Last Updated	May 25, 2007

Print Email Twitter Facebook MySpace AIM More

Last updated:	May 25, 2007
Author:	Caroline Rea, RN, BS, MS
Reviewed By:	Kathleen Romito, MD - Family Medicine
Editors:	Susan Van Houten, RN, BSN, MBA, Pat Truman, MATC

This information is not intended to replace the advice of a doctor. By using AOL Body, you indicate that you have read, understood, and agreed to our Terms of Service, and AOL Body Advertising Policy. Read more about our content partners.