Relationship between premenstrual symptoms and the ovarian cycle

Abstract

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 .