The majority of women of reproductive age experience physical and / or
emotional changes during the week to ten days before menstruation . In a
proportion - probably 3 - 5 % - these changes are severe , and constitute the
Premenstrual Syndrome ( PMS ) . The occurrence of these changes in the
premenstrual phase has caused many theorists to postulate an aetiological
link with the female reproductive cycle . The purpose of this research is to
investigate the relationship between premenstrual symptoms and the
ovarian hormones .
A review of the literature suggests that previous research has been
inconclusive for largely methodological reasons . These studies have
focussed on PMS and normal cycles , attempting to delineate
endocrinological differences between women with and without the
syndrome. Inconsistencies have arisen in the definition and diagnosis of
PMS and the frequency and type of assessment of ovarian activity . The
occurrence of symptoms in anovulatory or otherwise abnormal menstrual
cycles has received little attention . In this research , it was hypothesized that
a link between premenstrual changes and ovarian hormones would be
demonstrated by a change in symptomatology if the menstrual cycle were
naturally or artificially abnormal . Hence , the focus in these studies is on
premenstrual symptoms and their degree of change between cycles rather
than on the diagnosis of PMS .
Two studies were designed to investigate the hypothesis . The first
involved the observation of naturally occuring abnormal menstrual cycles ,
comparing them symptomatically with normal cycles in the same individual .
The second approach involved the comparison of women whose menstrual
cycles had been artificially manipulated by the long term use of low-dose
oral contraceptive ( oc ) pills , with matched women experiencing natural
cycles . In both of these studies, symptoms were assessed by daily
subjective ratings of eight physical and emotional variables using visual
analogue scales . In the first study , ovarian activity was assessed by the
analysis of daily , early morning urine samples for the major ovarian
hormone metabolites - oestrone-3-glucuronide and pregnane- diol-3aglucuronide
. In the second study , various components of the ovarian cycle
were assessed by the comparison of combined oc's having a constant dose
regime with oc's designed to mimic the normal cycle . In both studies daily ratings were continued for at least two complete cycles , and frequently
longer. The data were analysed in several ways , taking cognisance of the
inadequacy of conventional inferential statistical methods in this area .
Clear evidence emerged from these studies to show that neither
ovulation nor adequate luteal function are necessary for premenstrual
symptom occurrence . A relationship did emerge between the symptom of
breast tenderness and luteal hormones in approximately half of the women
studied . Absolute hormone levels did not seem to be involved in this effect,
suggesting a potential role for some other endocrine or biochemical factor
associated with luteal function .
The conclusions drawn from the study were that several different
aetiological mechanisms may be involved in the manifestation of
premenstrual symptoms . The relationship between symptoms and the
ovarian cycle would appear to be purely temporal in the majority of cases .
However , some symptoms , i.e. breast tenderness , may be more closely
related to luteal function in some women
