however , when pregnancy was maintained in ovariectomized hamsters by daily injections of 0.1 microgram 17 beta-estradiol and 4 mg progesterone , serum ir rose to levels similar to those in intact hamsters on days 10 and 14 of pregnancy ( i.e . 15 and 20 ng/ml , respectively ) .
C0033308
progesterone
C0032961
pregnancy