Analysis of menstrual calendars and serum α2-PEG in women on hormone replacement therapy for 12 months

Abstract

This study was conducted to assess endometrial protection in women on a cyclical combined hormone replacement regimen with 1 mg norethisterone BP, and to evaluate the use of the bleeding pattern and serum α 2-PEG in monitoring the endometrial response to exogenous hormone therapy. Fifty-one postmenopausal women attending the Menopause Research Unit at Leicester Royal Infirmary, UK, completed the study. All patients were at least 1 year after the menopause, with an average of 26 months since the last menstrual period. All women were prescribed a regimen of two tablets of Hormonin (oestriol 0.27 mg, oestrone 1.4 mg, and oestradiol 0.6 mg) continuously, with 1 mg of norethisterone added for 12 days out of each 28-day treatment cycle. Menstrual diaries were collected and analysed. The secretory changes were assessed by histology, menstrual bleeding pattern and a biological marker of secretory activity ( α 2-PEG). Withdrawal bleeding occurred on average on days 11, 12, 11, 12 and 13 on months 2, 3, 6, 9 and 12, respectively. There was a poor degree of consistency in the bleeding pattern. The level of α 2-PEG increased from the average baseline measurement of 2.7 ng/ml (S.D., 4.12) to 8.5 ng/ml (S.D., 4.16) after progestogen treatment. This rise, although significant, did not correlate with the uterine bleeding pattern. There was no statistically significant correlation between the level of α 2-PEG and endometrial histology. The findings highlight the fact that cycle predictability on HRT, as exemplified in this regimen, is poor. The level of α 2-PEG is a poor predictor of the endometrial histology and has a poor correlation with the day of onset of bleeding.