mean baseline e2 increased from 1,900 +/- 384 ( sem ) pg/ml in the first trimester to 3,520 +/- 849 in the second trimester ( p less than 0.05 ) and 43,057 +/- 5,765 pg/ml in the third trimester ( p less than 0.001 ) of pregnancy .
C0032980
second trimester
C0032961
pregnancy