Weeks 0 to 13 are known as the first trimester of pregnancy.
Because of normal variations in the size of infants during the third trimester , dating the pregnancy during this period is less reliable.
The researchers also found that cold temperatures in the third trimester of pregnancy caused birthweight to drop.
Additional information, such as use during pregnancy, can be monitored, and data on the use of certain drugs during the first trimester of pregnancy have been published.
In the second pregnancy trimester abnormal amniotic fetal cells can be detected.
Her mother, an anaesthetist, is in the second trimester of pregnancy.
More American women than ever are getting prenatal care in their first trimester of pregnancy.
In terms of congenital defects, the first trimester of pregnancy is the exposure period of interest.
She was on her first trimester (not for school) and was practically out of work when the loser bailed.
After the first trimester at Royce High School, I'd turned sixteen and dropped out.