( 2 ) in contrast with the hcg profile drug during pregnancy the free hcg-beta subunit exhibits a plasma concentration peak ( 400 +/- 132 ng/ml ; mean +/- 1 sd ) at the 12th-13th week , indicating that the changes in plasma levels of intact hcg and free hcg-beta subunit are unrelated .
C0032961
pregnancy
C0106132
hcg-beta