Menopause is the final menstrual period (FMP) and it marks the end of the woman’s child-bearing years. Every girl when she is born already has the finite number of oocytes, or eggs, to last her child-bearing years and she will obtain no new ova after birth. The basis of reproductive aging is oocyte depletion in the ovary5 with a steady loss of oocytes through atresia or ovulation throughout the child-bearing years, which does not necessarily occur at a constant rate.5 In fact even though the oocyte pool is depleted only about 500 ovulations have occurred over the child-bearing years.8
DEFINITION OF THE MENOPAUSE: The World Health Organization (1996) defines the menopause as the permanent cessation of menstruation resulting from loss of ovarian follicular activity.1 It is identified retrospectively by the absence of menstruation for one year1,4 or if the woman is charting her cycle has evidence that she has not ovulated for one year.6 Menopause occurs within a wide age range between the ages of 42 to 58,5 and the age of the menopause has not changed since ancient times. In the Massachusetts Women’s Health Study (ref 9, McKinlay), involving over 2500 women aged between 45-55 the median age of the final menstrual period (FMP) was 51.3 years.1,9
DEFINITION OF PRE-MENOPAUSE / PERIMENOPAUSE :
The perimenopause is a natural and healthy phase of a woman’s life but some women may have troubling symptoms associated with it.1 It is well recognized that the decline of fertility and the symptoms associated with this stage of life, become more evident the closer the menopause approaches. Therefore some researchers refer to the ‘pre-menopause’ as the five to eight years leading up to the menopause when the physiological decline in fertility has already begun, but without any noticeable clinical manifestations. The ‘peri-menopause’ refers to the years immediately preceding and the two years or so following the menopause when clinical manifestations are very much in evidence.6 The Massachusssetts study9 found that the median age of the peri-menopause, based on the appearance of menstrual irregularity was 47.5 years, with the length of the typical ‘menopausal transition’ estimated at nearly 4 years.1,9 For a given interval of amenorrhoea the probability that menopause has occurred increases with age.10 “An amenorrheic interval of 6 months is predictive of menopause in 45% of women aged 45-49 years and in 70% of women over 53 years of age. That is 50% and 30% of women in those respective age groups could be expected to have one or more additional episodes of menstruation after 6 months without menses.”10
- Liu JH, Gass ML; ‘Management of the perimenopause’; 2006; Pub. McGraw-Hill, ISBN 0-0-142281-1
- Odeblad Erik; ‘The discovery of different types of cervical mucus and the Billings Ovulation Method’; Bulletin of the Ovulation Method Research and Reference Centre of Australia, Vol 21, No3; 3-35; Sept 1994. (on the internet if you google ‘Erik Odeblad, cervical mucus’).
- Odeblad E, ‘Investigations on the physiological basis for fertility awareness’ page 7; Bulletin for the Ovulation Method Research and ReferenceCentre of Australia, vol 29, no 1, p2-11, march 2002, (internet, Billings Ovulation Method)
- Flynn A, Brooks M; ‘The Manual of Natural Family Planning’; pages 74-80; 1996; ISBN 0 7225 3115 X
- Soules MR, Sherman S, Parrot E et al; Executive summary: Stages of Reproductive Aging Workshop (STRAW). Fertil Steril. 2001; 76: 874
- Flynn A, Worthington W; ‘Teachers Training Manual’; ‘symptothermal multiple index method’ of natural family planning.
- Harlow S D, Mitchell ES, Crawford S; ‘The ReStage Collaboration: defining optimal bleeding criteriafor onset of early menopausal transition’; Fertil Steril; vol 89, No1, Jan 2008.
- Alvero Ruben, Schlaff William D; ‘Reproductive endocrinology and infertility, The Requisites in Obstetrics and Gynecology’; 2007, page 229; ISBN-13:978-0-323-04054-9
- McKinlay SM; ‘The normal menopause tradition: and overview ‘; Maturitas; 1996; 23:137
- Wallace RB, Sherman BM et al; ‘Probability of menopause with increasing duration of amenorrhea in middle-aged women’; Am. J. Obstet. Gynecol. 135: 1021, 1979.
- Richardson SJ, Senikas V, Nelson JF; ‘Follicular depletion during the menopausal transition: evidence for accelerated loss and ultimate exhaustion’; J Clin Endocrinol Metab. 1987; 65:1231
- Brown JB; ‘Types of ovarian activity in women and their significance: the continuum (a reinterpretation of early findings)'; Human Reproduction Update; Vol 17; No 2; p141-158. (this is a classic article which gives a greater understanding of the menstrual cycle throughout the reproductive life).
- Cynthia A. Stuenkel, MD, Margery Gass MD et al; ‘A decade after the Women’s Health Initiative – the experts agree'; Fertility and Sterility; vol 98, no 2; August 2012; p313-314.