hydroxyproline contents of the normal placenta in the 1st , 2nd and 3rd trimester were 7.2 +/- 1.1 , 14.6 +/- 4.4 and 23.4 +/- 4.8 micrograms/mg protein , respectively , and increased linearly as the pregnancy progressed ( p less than 0.01 , r = 0.8753 ) .
C0032981
3rd trimester
C0032961
pregnancy