Endocrinology of menopausal transition
Research project leader: Prof Henry Burger, email: henry.burger
As women age, the ovary loses its complement of egg-containing follicles. This decline causes the interplay between the ovary and the pituitary to become increasingly irregular. This can result in changes to menstrual cycle patterns and symptoms such as hot flushes, excessive bleeding, increased bone breakage and mood swings.
We are studying the endocrine features of individual ovulatory and anovulatory cycles in women in late reproductive age and during stages of the menopause transition. We propose a classification of menstrual cycles, suggestive of progressively impaired ovarian function. As part of our ongoing investigation of hormone changes in menopause, we have recently conducted studies with researchers at the University of Sydney and the University of Saskatchewan.
We collaborated with Dr Georgina Hale and Professor Ian Fraser of Sydney we conducted a large clinical study involving 77 women in their mid or late reproductive stages. The women were tested three times per week during menstruation to determine levels of the reproductive hormones serum FSH, LH, E2, progesterone, inhibin A, inhibin B, Anti Mullerian Hormone.
We have currently been working closely with the research team at University of Saskatchewan, to investigate the changes in circulating hormone levels, ovarian follicle number and cyclic pattern in menstrual cycles as menopause approaches. During this research, we found that ovarian and pituitary hormones involved in this interplay became disorganised in the late stages of menstruation, for example, with evidence of normal hormone patterns one cycle and abnormal patterns the next. In some cases, irregular hormone activity during the late stages of menstruation was even shown to cause the unusual occurrence of two ovulations in one cycle.
We believe that many of the difficulties experienced by women approaching menopause are due to irregular activity by the pituitary and ovary. These studies will provide us with a clearer understanding of this process, which will help in developing better treatments in women experiencing a difficult menopause transition.
National Health and Medical Research Council
Hale GE, Hughes CL, Burger HG, Robertson DM, Fraser IS. Atypical estradiol secretion and ovulation patterns caused by luteal out-of-phase (LOOP) events underlying irregular ovulatory menstrual cycles in the menopausal transition. Menopause. 2009 Jan-Feb;16(1):50-9.
Robertson DM, Hale GE, Jolley D, Fraser IS, Hughes CL, Burger HG. Interrelationships between ovarian and pituitary hormones in ovulatory menstrual cycles across reproductive age. J Clin Endocrinol Metab. 2009 Jan;94(1):138-44.
Burger HG, Hale GE, Dennerstein L, Robertson DM. Cycle and hormone changes during perimenopause: the key role of ovarian function. Menopause. 2008;15(4 Pt 1):603-12.
Healy DL, Bell R, Robertson DM, Jobling T, Oehler MK, Edwards A, et al. Ovarian status in healthy postmenopausal women. Menopause. 2008 Nov-Dec;15(6):1109-14.
Robertson DM. Anti-Mullerian hormone as a marker of ovarian reserve: an update. Womens Health (Lond Engl). 2008 Mar;4(2):137-41.
Robertson DM, Hale GE, Fraser IS, Hughes CL, Burger HG. A proposed classification system for menstrual cycles in the menopause transition based on changes in serum hormone profiles. Menopause. 2008 Nov-Dec;15(6):1139-44.