Ovulatory Menstrual Cycles Research Articles

Pregnancy in End Stage Renal Disease

The ovulatory menstrual cycle is known to be affected on multiple levels in women with advanced renal disease. Menstrual irregularities, sexual dysfunction, and infertility worsen in parallel with the renal disease. Pregnancy in women with ESRD on dialysis is therefore uncommon. Furthermore, when pregnancy does occur, it can prove hazardous to both mother and baby owing to a multitude of potential complications including accelerated hypertension and preeclampsia, poor fetal growth, anemia, and polyhydramnios. Data are emerging, however, to suggest that pregnancy while on intensified renal replacement regimens may result in better pregnancy outcomes, and emerging trends include the decreased rate of therapeutic abortions probably reflecting a change in counseling practices over time. Nevertheless, a pregnant woman on intensive dialysis requires meticulous follow-up by a dedicated team including nephrology, obstetrics, and a full multidisciplinary staff. In this article, we will address fertility issues in young women with ESRD, review pregnancy outcomes in women on both hemodialysis and peritoneal dialysis, and provide suggestions for the management of the pregnant women on intensive hemodialysis.

Changes in serum antimüllerian hormone levels across the ovulatory menstrual cycle in late reproductive age

The aim of this study was to assess the pattern of serum antimüllerian hormone (AMH) across the normal ovulatory menstrual cycle in women in late reproductive age when ovarian follicle reserve and, hence, serum AMH levels are reduced. Serum AMH levels were determined by enzyme-linked immunosorbent assay across the ovulatory menstrual cycle from women in mid (n = 18) and late (n = 43) reproductive life, including the menopausal transition. : No intracycle variation in AMH level was observed in women in mid reproductive life nor in 33% (n = 14) of women with normal ovulatory cycles in late reproductive age. In the remaining cycles, a significant 2-fold decrease (P < 0.01) in AMH in 11 cycles and a significant 4.2-fold increase (P < 0.01) in 10 cycles were observed between the follicular and luteal phases. In a further eight ovulatory cycles, AMH was below the level of assay detection. As ovarian follicle reserve decreases with age and AMH levels are reduced, separate patterns of AMH are detected in the follicular and luteal phases of ovulatory menstrual cycles, presumably reflecting the intermittent pattern of the emergence of follicles close to menopause. It is concluded that when AMH levels are substantially reduced, as in late reproductive age, they become less reliable as markers of ovarian reserve because of the changing patterns observed in some cycles.

Dynamics of the primate ovarian surface epithelium during the ovulatory menstrual cycle

Epithelial ovarian cancer (EOC) risk correlates strongly with the number of ovulations that a woman experiences. The primary source of EOC in women is the ovarian surface epithelium (OSE). Mechanistic studies on the etiology of OSE transformation to EOC cannot be realistically performed in women. Selecting a suitable animal model to investigate the normal OSE in the context of ovulation should be guided by the model's reproductive similarities to women in natural features that are thought to contribute to EOC risk. We selected the non-human primate, rhesus macaque, as a surrogate to study the normal OSE during the natural menstrual cycle. We investigated OSE morphology and marker expression, plus cell proliferation and death in relation to menstrual cycle stage and ovulation. OSE cells displayed a morphological range from squamous to columnar. Cycle-independent parameters and cycle-dependent changes were observed for OSE histology, steroid receptor expression, cell death, DNA repair and cell adhesion. Contrary to findings in non-primates, primate OSE cells were not manifestly cleared from the site of ovulation, nor were proliferation rates affected by ovulation or stage of the menstrual cycle. DNA repair proteins were more highly expressed in OSE than in other ovarian cells. This study identifies significant differences between primate and non-primate OSE. In contrast to established views, ovulation-induced death and proliferation are not indicated as prominent contributors to EOC risk, but disruption of OSE cadherin-mediated adhesion may be, as could the loss of ovary-mediated chronic suppression of proliferation and elevation of DNA repair potential.

Modifications of EEG Activity Related to Perception of Emotionally Colored, Erotic, and Neutral Pictures in Women during Different Phases of the Ovulatory (Menstrual) Cycle

We studied modifications of EEG activity related to perception of visual stimuli (pictures) of the International Affective Picture System (IAPS) in women during different phases of the ovulatory (menstrual) cycle. We found that the woman’s brain is most intensely activated by both emotionally negative and positive visual stimuli during the follicular phase of the ovulatory cycle, while such activation is minimum during ovulation per se. Upon the action of neutral stimuli, cerebral activation was the most intense during the lutein phase (compared with that within other phases); manifestations of activation were concentrated in the right hemisphere. Cognitive and emotional components of perception of affective pictures were expressed to a greatest extent in the course of viewing positive stimuli during the follicular phase. Perception of emotionally pleasant stimuli during other phases was accompanied by lateralization of activation of sensory and analytical processes in the left hemisphere during the ovulatory phase and in the right hemisphere within the lutein phase. The viewing of emotionally negative pictures during the follicular phase led to a rise in the power of theta oscillations in the left frontal region and also to depression of the alpha activity in central/parietal parts of the left hemisphere, which can result from aggravation of anxiety and verbally shaped disturbing ideas upon the action of such stimuli. Presentation of erotically colored visual stimuli caused the most intense changes in the EEG, which depended on the phases of the ovulatory cycle, during post-stimulation time interval but not during the viewing of pictures itself.

Circadian variation of sleep during the follicular and luteal phases of the menstrual cycle.

Women experience insomnia more frequently than men. Menstrual cycle changes in reproductive hormones and circadian rhythms may contribute to sleep disruptions. Our aim, therefore, was to clarify the interaction between menstrual and circadian processes as it affects sleep. Participants entered the laboratory during the mid-follicular (MF) and mid-luteal (ML) phases of their menstrual cycle for an ultra-rapid sleep-wake cycle (URSW) procedure, consisting of 36 cycles of 60-min wake episodes alternating with 60-min nap opportunities. This procedure concluded with an ad libitum nap episode. Time-isolation suite. Eight unmedicated, physically and mentally healthy females with regular ovulatory menstrual cycles. N/A. Polysomnographic sleep from nocturnal sleep episodes and 60-min naps; subjective alertness; core body temperature (CBT); salivary melatonin; urinary estradiol; and urinary progesterone. Increased CBT values at night and decreased CBT amplitude were observed during ML compared to MF. Circadian phase of CBT and the circadian melatonin profile were unaffected by menstrual phase. All analyzed sleep parameters showed a circadian variation throughout the URSW procedure, with no menstrual phase differences observed for most, including slow wave sleep (SWS). The circadian variation of REM sleep duration, however, was sensitive to menstrual phase, with reduced REM sleep during ML at circadian phase 0 degrees and 30 degrees. Moderate but significant changes in REM sleep across the menstrual and circadian cycles were observed. These results support an interaction between circadian and menstrual processes in the regulation of REM sleep.

Plasma levels of C-reactive protein, leptin and glycosaminoglycans during spontaneous menstrual cycle: differences between ovulatory and anovulatory cycles

To assess the plasma levels of the inflammatory markers such as C-reactive protein (CRP), leptin, and glycosaminoglycans (GAGs) during the menstrual cycle. Eighteen healthy volunteers were divided into two groups according to the presence of ovulatory or anovulatory menstrual cycles. Blood samples were collected at different time points: at the menstrual phase (days 2-3), periovulatory phase (days 12-13), and luteal phase (days 23-24). CRP and leptin concentrations were measured by enzyme immunoassay. GAGs were isolated using ion-exchange chromatography on DEAE-Sephacel and quantified as hexuronate. The structural characterization of chondroitin sulfate (CS) isomers was performed by fluorophore-assisted carbohydrate electrophoresis (FACE). In the women with ovulatory cycles, plasma GAG levels differed significantly during menstrual cycle, with increased values at the periovulatory with respect to the menstrual phase. No significant differences in CRP and leptin concentrations were observed through the menstrual cycle in both the examined cycles, but inter-group analysis revealed significant differences of CRP and leptin levels between the ovulatory and anovulatory cycles with higher values at periovulatory phase in the ovulatory cycles. There are no fluctuations of both total GAG concentration and CS isomer content during menstrual cycle in the anovulatory cycles. A significant correlation between CRP and gonadotrophins was found. There is no significant difference in CRP across the menstrual cycle among ovulatory cycles, but there is a trend toward higher CRP at the periovulatory than the other phases, consistent with the significant difference in CRP between ovulatory and anovulatory cycles at the periovulatory phase. Both the trend and the significant result suggest an elevation in CRP with ovulation. These observations provide additional evidences to the hypothesis that the ovulation is an inflammatory-like phenomenon.

Menstrual phase-related differences in the pulsatility index on the central retinal artery suggest an oestrogen vasodilatation effect that antagonizes with progesterone

The actual effect of steroid hormones on cerebral microcirculation is still controversial. Therefore, the aim of our study was to investigate vascular flow variations in the central retinal artery that may exist during the ovulatory menstrual cycle. A total of 34 healthy women were included in this observational, longitudinal, and prospective study. All participants were submitted to dopplerfluxometric evaluation of the eyes in order to study the pulsatility index (PI) of the central retinal arteries, during four phases of the menstrual cycle: early follicular, mid follicular, periovulatory, and mid luteal phases. Subjects' ages ranged from 14 to 47 years old (mean: 29.7 ± 10.1) and PI did not differ among age groups. The PI of the central retinal artery was different among the four phases of the menstrual cycle. PI showed a significant decrease from early follicular phase (1.72) to mid follicular phase (1.57) (p = 0.037), and was similar during periovulatory phase (1.56) and significantly increased in mid luteal phase (1.70). After that it returned to the values observed in the early follicular phase. Our results suggest the existence of an oestrogen vasodilatation effect on the central retinal artery that is menstrual phase-related and antagonized by progesterone.

Bifurcation analysis of a model for hormonal regulation of the menstrual cycle

A model for hormonal control of the menstrual cycle with 13 ordinary differential equations and 41 parameters is presented. Important changes in model behavior result from variations in two of the most sensitive parameters. One parameter represents the level of estradiol sufficient for significant synthesis of luteinizing hormone, which causes ovulation. By studying bifurcation diagrams in this parameter, an interval of parameter values is observed for which a unique stable periodic solution exists and it represent an ovulatory cycle. The other parameter measures mass transfer between the first two stages of ovarian development and is indicative of healthy follicular growth. Changes in this parameter affect the uniqueness interval defined with respect to the first parameter. Hopf, saddle-node and transcritical bifurcations are examined. To attain a normal ovulatory menstrual cycle in this model, a balance must be maintained between healthy development of the follicles and flexibility in estradiol levels needed to produce the surge in luteinizing hormone.

Analysis of testosterone pulsatility in women with ovulatory menstrual cycles

To evaluate the pattern of the pulsatile secretion of testosterone in normal menstrual cycle. Eight healthy women with ovulatory menstrual cycles were enrolled. Blood samples were collected at ten-minute intervals for six hours, starting between 7 and 8 am, after a ten-hour fasting, in three phases: mid-follicular (Day 7), late follicular (Day 12) and mid-luteal phase (Day 21). Samples were assayed for testosterone, LH and the baseline also for SHBG. Testosterone pulse frequency, mean amplitude pulse, percentage of increment in pulse amplitude, mean duration of pulses and pulse interval were similar in the three phases. LH pulsatility was statistically different among the three phases (p < 0.001) representing normal ovulatory cycles. These data increase the knowledge about the testosterone secretion profile in the human menstrual cycle and can be used as a contribution to clinical investigation in both hyperandrogenism and androgen insufficiency syndrome.

Ovulation disturbances and mood across the menstrual cycles of healthy women

We examined the cyclicity of negative mood relative to ovulation and ovulation disturbances in Menstrual Cycle Diary© data collected daily during a 1-year study of ovulation, exercise, and bone change. A validated quantitative basal temperature-based methodology was used to determine the onset of the luteal phase. ‘Feeling depressed’, ‘feeling anxious’, and ‘feeling angry/frustrated’ were scored on a scale of 0 (absent) to 4 (very intense). Mood scores were examined over two 15-day intervals centered on either ovulation/midpoint, or on the onset of flow. Data were available from 765 cycles of 62 healthy and initially ovulatory women with a mean age of 33.9 ± 5.4 years. Of 739 cycles that could be classified, 532 (72%) were normally ovulatory, 185 (25%) were ovulatory with a short (<10 day) luteal phase, and 22 (3%) were anovulatory. Minor cyclic mood changes were present in both ovulatory and anovulatory menstrual cycles. In anovulatory cycles, mood tended to be more variable but less negative, with a time course that differed from that in ovulatory cycles. Mood scores did not differ based on luteal phase length or with hormone levels. Patterns and mechanisms of mood change in very symptomatic women appear to be essentially amplifications of normal experiences.

Fresh Ovarian Tissue and Whole Ovary Transplantation

A series of monozygotic (MZ) twin pairs discordant for premature ovarian failure presented an unusual opportunity to study ovarian transplantation. Ten MZ twin pairs requested ovarian transplantation and nine have undergone transplantation with cryopreservation of spare tissue. Eight had a fresh cortical tissue transplant, one of whom received a second frozen-thawed transplant after the first ceased functioning at 3 years. One had a fresh microvascular transplant. All recipients reinitiated ovulatory menstrual cycles and normal day 3 serum follicle-stimulating hormone levels by 77 to 142 days. Seven have already conceived naturally (three twice). Currently, seven healthy infants have been delivered out of 10 pregnancies. The oldest transplant ceased functioning by 3 years, but then she conceived again after a frozen-thawed secondary transplant. There was no apparent difference in return of ovarian function between the nine fresh ovarian grafts and the one frozen graft. Ovarian transplantation appears to restore ovulatory function robustly. Ten pregnancies, leading to seven healthy infants, including one after cryopreservation, bode well for application to fertility preservation.

Exercise and Premenstrual Symptomatology: A Comprehensive Review

Premenstrual syndrome (PMS) refers to a constellation of regular, recurring, psychological or somatic complaints, or both, that occur specifically during the luteal phase of the ovulatory menstrual cycle and that resolve by the onset of or during menstruation. Many women of reproductive age experience PMS. Exercise has been proposed as a potential treatment in this regard, and several observational studies have reported a reduction in PMS and associated symptomatology in physically active women relative to their less active counterparts. This review seeks to synthesize the available literature regarding the effects of exercise on PMS, with emphasis on findings from intervention studies. Studies were identified by systematically searching relevant databases. Four eligible intervention studies were identified; all of these reported a reduction in PMS and related symptomatology after participation in exercise interventions. However, studies to date have recruited small samples and have been of low methodological quality. There is a paucity of research on the effects of exercise on PMS. Although the American College of Obstetricians and Gynecologists (ACOG) has advised that regular aerobic exercise may help relieve PMS, to make any evidence-based policy recommendations regarding the effectiveness of exercise, more high-quality research is required.

Atypical estradiol secretion and ovulation patterns caused by luteal out-of-phase (LOOP) events underlying irregular ovulatory menstrual cycles in the menopausal transition

The menopausal transition is characterized by irregular menstrual cycles and unpredictable hormone levels, including dramatic swings in estradiol (E2). An increasing number of studies have found variable high E2 and low luteal phase progesterone occur with progression of Stages of Reproductive Aging Workshop (STRAW)stage, but the cause remains unclear. To explore the causes of the erratic changes in E2, individual within-cycle secretion patterns of E2, progesterone, follicle-stimulating hormone, luteinizing hormone, inhibin A, and inhibin B were explored in detail. Blood samples taken three times per week over 1 1/3 menstrual cycles from 77 women aged 21 to 55 classified as mid-reproductive age (STRAW stages 5 and 4; n = 21), late-reproductive age (STRAW stages 4 and 3; n = 16), early menopausal transition (STRAW stage 2; n = 17), and late menopausal transition (STRAW stage 1; n = 23) were analyzed. Eleven of the 29 (37%) early and late menstrual transition ovulatory cycles exhibited a specific pattern of E2 secretion that was characterized by a second increase in E2 during the mid- and late luteal phases and that continued to a peak during the subsequent menstrual phase. This second rise and fall in E2 was typical in appearance of a normal follicular phase, except that it was superimposed on an existing ovulatory cycle(specifically during the luteal and menstrual phases). The pattern was therefore referred to as a luteal out-of-phase(LOOP) follicular event. In four of these LOOP cycles, a luteinizing hormone peak and ovulatory episode followed the second E2 peak early in the subsequent cycle. Compared with the typical ovulatory cycles, the cycles with LOOP events exhibited lower luteal phase progesterone, higher early cycle follicle-stimulating hormone, and lower early cycle inhibin B. They were also associated with abnormally short (<21 d) or long (>40 d) cycle length. Many of the marked increases in ovulatory cycle E2 and cycle irregularities during the menopausal transition may be due to LOOP events and appear to be triggered by prolonged high follicular phase follicle-stimulating hormone levels.

Scanning electron and light microscopy study of the cervical mucus in women with polycystic ovary syndrome

Two types of cervical mucus are recognized, oestrogenic and gestagenic. These are constituted by different subtypes, and their characteristics change depending on variations in the hormonal levels and on the existence of several pathologies. Our aim was to identify the ultrastructure and crystallization characteristics of the cervical mucus in women suffering from polycystic ovary syndrome, and to compare these characteristics with those of normal control women. Cervical mucus samples were taken from 10 women, 4 control group women (with normal ovulatory menstrual cycles) and 6 suffering from polycystic ovary syndrome (2 with ovulatory and 4 with anovulatory cycles). This mucus was characterized according to its ultrastructure and crystallization. The type of mucus obtained was related to the levels of oestradiol and progesterone present when the samples were taken. As regards mucus ultrastructure, differences were found between the control women and those with polycystic ovary syndrome and anovulatory menstrual cycles. Such variations were evident in the type of mesh and the average diameter of the mucus pores. Mucus crystallization in control women showed the usual oestrogenic disposition: fern-like (L, P2), rectilinear (S) or a hexagonal structure (P6). On the other hand, in women with polycystic ovary syndrome, indefinite mucus crystallizations were found, as well as crystallization patches resembling oestrogenic and gestagenic-like mucus. This study shows that the ultrastructure and crystallization characteristics of the cervical mucus in polycystic ovary syndrome women are different from those of control women. The latter would be dependent on their levels of oestradiol and progesterone.

Interrelationships between Ovarian and Pituitary Hormones in Ovulatory Menstrual Cycles across Reproductive Age

Ovarian hormones regulate pituitary gonadotropin secretion across the menstrual cycle via negative and positive feedback mechanisms. The contribution of individual hormones is complex and is a continuing area of research. The aim of the study was to identify relationships between LH/FSH and estradiol, progesterone, inhibin A, inhibin B, and anti-Mullerian hormone (AMH) in ovulatory menstrual cycles across reproductive age. Serum ovarian and pituitary hormones were studied in a group of young (<35 yr; n = 21) and older (>45 yr; n = 55) women. The slopes of the regression lines relating the ovarian and pituitary hormones were determined by multiple linear regression analysis and expressed with 95% confidence intervals for each ovarian hormone, with FSH and LH as independent variables. Both simultaneous and delayed (time lagged) relationships were examined. Clear associations were evident for the lagged prediction of FSH, with significant negative associations being evident with inhibin B and AMH in the follicular phase and with estradiol, inhibin B, progesterone, and AMH in the luteal phase. For the lagged prediction of LH, significant positive and negative associations were observed with estradiol and inhibin B, respectively, in the follicular phase and a negative association with progesterone and inhibin B in the luteal phase. It is concluded that in the follicular phase, inhibin B is a major feedback regulator of FSH and may also be a negative feedback regulator of LH. AMH may be indirectly involved in FSH regulation.

Reduced parasympathetic activity during sleep in the symptomatic phase of severe premenstrual syndrome

Objective Severe premenstrual syndrome (PMS) is a common distressing disorder in women that manifests during the premenstrual (late-luteal) phase of the ovulatory menstrual cycle. There is some evidence that altered autonomic function may be an important component of PMS, but few studies have used heart rate variability (HRV) as a sensitive marker of autonomic activity in severe PMS, and findings are conflicting. Methods We investigated HRV during sleep, a state that is relatively free of external disruptions, in 9 women with severe PMS and 12 controls. Results The normal-to-normal (NN) RR interval was shorter during the sleep period in women with PMS than in controls in both the follicular and the late-luteal phases of the menstrual cycle. The standard deviation of all NN intervals, a measure of total variability in the interbeat interval, was lower during the sleep period in the late-luteal phase than in the follicular phase in women with PMS. The square root of the mean of the sum of the squares of differences between adjacent NN intervals, a measure reflecting high-frequency (HF) activity, showed a similar pattern. HF power, a marker of parasympathetic activity, was lower during non-rapid eye movement (non-REM) and REM sleep in the late-luteal phase than in the follicular phase in women with severe PMS. Controls had a shorter NN interval, but similar HRV measures, in the late-luteal phase compared with the follicular phase. Conclusion These results suggest that women with severe PMS have decreased parasympathetic activity during sleep in association with their premenstrual symptoms in the late-luteal phase compared with the follicular phase when they are symptom-free.

The Pathophysiology of Amenorrhea in the Adolescent

Menstrual irregularity is a common occurrence during adolescence, especially within the first 2-3 years after menarche. Prolonged amenorrhea, however, is not normal and can be associated with significant medical morbidity, which differs depending on whether the adolescent is estrogen-deficient or estrogen-replete. Estrogen-deficient amenorrhea is associated with reduced bone mineral density and increased fracture risk, while estrogen-replete amenorrhea can lead to dysfunctional uterine bleeding in the short term and predispose to endometrial carcinoma in the long term. In both situations, appropriate intervention can reduce morbidity. Old paradigms of whom to evaluate for amenorrhea have been challenged by recent research that provides a better understanding of the normal menstrual cycle and its variability. Hypothalamic amenorrhea is the most prevalent cause of amenorrhea in the adolescent age group, followed by polycystic ovary syndrome. In anorexia nervosa, exercise-induced amenorrhea, and amenorrhea associated with chronic illness, an energy deficit results in suppression of hypothalamic secretion of GnRH, mediated in part by leptin. Administration of recombinant leptin to women with hypothalamic amenorrhea has been shown to restore LH pulsatility and ovulatory menstrual cycles. The use of recombinant leptin may improve our understanding of the pathophysiology of hypothalamic amenorrhea in adolescents and may also have therapeutic possibilities.

The Relationship between Circulating Leptin and Plasma Female Sex Hormone Levels in Physically Active Regularly Menstruating Premenopausal Women with Ovulatory and Anovulatory Menstrual Cycles

The Relationship between Circulating Leptin and Plasma Female Sex Hormone Levels in Physically Active Regularly Menstruating Premenopausal Women with Ovulatory and Anovulatory Menstrual Cycles

A series of monozygotic twins discordant for ovarian failure: ovary transplantation (cortical versus microvascular) and cryopreservation

A series of monozygotic (MZ) twin pairs discordant for premature ovarian failure presented an unusual opportunity to study ovarian transplantation. Ten MZ twin pairs requested ovarian transplantation and eight have undergone transplantation with cryopreservation of spare tissue. Seven had a fresh cortical tissue transplant, one of whom received a second frozen-thawed transplant after the first ceased functioning at three years. One had a fresh microvascular transplant. All recipients reinitiated ovulatory menstrual cycles and normal Day 3 serum FSH levels by 77-142 days. Six have already conceived naturally (one twice). Currently, two healthy babies have been delivered, and another three pregnancies are ongoing. The oldest transplant functioned for 36 months, resulting in one child and one miscarriage. She conceived again after a frozen-thawed secondary transplant. There was no apparent difference in return of ovarian function between the eight fresh ovarian grafts and the one frozen graft. Ovarian transplantation appears to restore ovulatory function robustly. Successful pregnancies, including one after cryopreservation, bode well for application to fertility preservation.

T01-O-06 Female sexuality may be modified by olfactory and auditory thresholds

Objective To study the effect of olfactory and auditory thresholds in modifying sexuality in woman. Material and Methods 60 premenopausal women (meanage 28.2±4.1 years, range18-37). Underwent sexual history interview, and the Personal Experiences Questionnaire (PEQ) was self-administrated. By a prospective study, we measured the olfactometric and audiometric variations - by olfactometry and auditory evoked potentials (AEP)- during the follicular, periovular and luteal phases of one ovulatory menstrual, and during third month of pill intake. Pill users were considered as a control group. The second control group was constituted by 18 premenopausal women with menstrual cycle without ovulation, that had been excluded from this study during enrolment. Results Both olfactometric and audiologic thresholds reached a higher sensitivity during the follicular and periovular phases than during the luteal phase. Olfactometric and audiologic thresholds during contraceptive use were similar to those of the luteal phase. Comparing the cyclic variations of both olfactometric and audiometric sexual activity seem to be increased in a linear correlation manner during periovular phase of ovulatory menstrual cycle, with respect to the other menstrual phases or in both control groups. Conclusion From our study, it seems to be an interaction among sensitivity, sexual activity and menstrual cycle in human. These physiological sensorial changes occurring during menstrual cycle may modulate the sexual behaviour, often acting unconsciously.