Oestrogen and progesterone receptors in the human vagina during the menstrual cycle, pregnancy and postmenopause.

Oestrogen receptor (ER) and progesterone receptor (PR) concentrations were measured by enzyme immunoassays in human vaginal tissues. There were no significant differences in either case between the follicular and luteal phases, or in ER concentrations between regularly cycling and postmenopausal women. ER levels were significantly lower in pregnant than in non-pregnant women. PR levels were significantly lower in both postmenopausal and pregnant women than in regularly cycling women. A positive correlation between ER and PR was found in pregnant women and there were correlations between ER and both oestradiol and prolactin in postmenopausal women. This is the first study to compare both ER and PR in the human vagina during the menstrual cycle, pregnancy and postmenopause.