comparison of hormone values in peripheral and utero-ovarian vein samples from ovaries with and without corpora lutea ( days 7 , 9 , 13 , 21 , 40 and 60 of pregnancy ) showed that : ( a ) progesterone was secreted by the corpus luteum until at least day 40 by which time there was also placental secretion ;
C0032961
pregnancy
C0033308
progesterone