serum levels of progesterone ( p4 ) , 17 alpha-hydroxyprogesterone ( 17-ohp ) , androstenedione ( delta ) and estradiol ( e2 ) reached their zenith on day 14 of hamster pregnancy but were not associated with increases in serum pituitary gonadotropins or placental lactogen ( day 1 = day of sperm in vaginal smear ) .
C0014912
estradiol
C0032961
pregnancy