Luteinizing Hormone in Premenopausal Women May Stimulate Uterine Leiomyomata Development

Genetic liability to multiple factors and uterine leiomyoma risk: a Mendelian randomization study

Background and objective

Uterine leiomyoma is the most common benign tumor in females of reproductive age. However, its causes have never been fully understood. The objective of our study was to analyze the causal association between various factors and uterine leiomyoma using Mendelian randomization (MR).

Methods

Genetic variables associated with risk factors were obtained from genome-wide association studies. Summary-level statistical data for uterine leiomyoma were obtained from FinnGen and the UK Biobank (UKB) consortium. We used inverse variance weighted, MR-Egger, and weighted median methods in univariate analysis. Multivariable MR analysis was used to identify independent risk factors. A fixed-effect model meta-analysis was used to combine the results of the FinnGen and UKB data.

Results

In the FinnGen data, higher genetically predicted age at natural menopause, systolic blood pressure (SBP), diastolic blood pressure (DBP), and fasting insulin were associated with an increased risk of uterine leiomyoma, while higher age at menarche was associated with a reduced risk of uterine leiomyoma. Multivariable MR analysis of SBP and DBP showed that higher DBP might be an independent risk factor of uterine leiomyoma. In the UKB data, the results for age at natural menopause, SBP, DBP, and age at menarche were replicated. The result of the meta-analysis suggested that uterine leiomyoma could also be affected by polycystic ovary syndrome (PCOS), endometriosis, and 2-hour glucose level.

Conclusion

Our MR study confirmed that earlier menstrual age, hypertension, obesity, and elevated 2-hour glucose post-challenge were risk factors for uterine leiomyoma, and the causal relationship between smoking and uterine leiomyoma was ruled out. In addition, later age of menopause and endometriosis were found to increase the risk of uterine leiomyoma, while PCOS was found to decrease the risk.

Uterine Fibroids: Hiding in Plain Sight

Uterine fibroids (leiomyomas) are present in >75% of women and can cause serious morbidity. They are by far the leading cause of hysterectomy. Fibroids are a complex mixture of cells that include fibroblasts and smooth muscle cells. Rich in extracellular matrix, they typically arise through somatic mutations, most commonly MED12. Their lack of growth inhibition and their ability to have facets of malignancy yet be histologically and biologically benign provide opportunities to explore basic processes. To date, the mechanisms responsible for growth and development of leiomyomas are an enigma. This review provides an overview of current understanding and future directions for clinical and basic research of fibroids.

A prospective cohort study of ambient air pollution exposure and risk of uterine leiomyomata

STUDY QUESTION

To what extent are ambient concentrations of particulate matter <2.5 microns (PM2.5), nitrogen dioxide (NO2) and ozone (O3) associated with risk of self-reported physician-diagnosed uterine leiomyomata (UL)?

SUMMARY ANSWER

In this large prospective cohort study of Black women, ambient concentrations of O3, but not PM2.5 or NO2, were associated with increased risk of UL.

WHAT IS KNOWN ALREADY

UL are benign tumors of the myometrium that are the leading cause of gynecologic inpatient care among reproductive-aged women. Black women are clinically diagnosed at two to three times the rate of white women and tend to exhibit earlier onset and more severe disease. Two epidemiologic studies have found positive associations between air pollution exposure and UL risk, but neither included large numbers of Black women.

STUDY DESIGN, SIZE, DURATION

We conducted a prospective cohort study of 21 998 premenopausal Black women residing in 56 US metropolitan areas from 1997 to 2011.

PARTICIPANTS/MATERIAL, SETTING, METHODS

Women reported incident UL diagnosis and method of confirmation (i.e. ultrasound, surgery) on biennial follow-up questionnaires. We modeled annual residential concentrations of PM2.5, NO2 and O3 throughout the study period. We used Cox proportional hazards regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for a one-interquartile range (IQR) increase in air pollutant concentrations, adjusting for confounders and co-pollutants.

MAIN RESULTS AND THE ROLE OF CHANCE

During 196 685 person-years of follow-up, 6238 participants (28.4%) reported physician-diagnosed UL confirmed by ultrasound or surgery. Although concentrations of PM2.5 and NO2 were not appreciably associated with UL (HRs for a one-IQR increase: 1.01 (95% CI: 0.93, 1.10) and 1.05 (95% CI: 0.95, 1.16), respectively), O3 concentrations were associated with increased UL risk (HR for a one-IQR increase: 1.19, 95% CI: 1.07, 1.32). The association was stronger among women age <35 years (HR: 1.26, 95% CI: 0.98, 1.62) and parous women (HR: 1.28, 95% CI: 1.11, 1.48).

LIMITATIONS, REASONS FOR CAUTION

Our measurement of air pollution is subject to misclassification, as monitoring data are not equally spatially distributed and we did not account for time-activity patterns. Our outcome measure was based on self-report of a physician diagnosis, likely resulting in under-ascertainment of UL. Although we controlled for several individual- and neighborhood-level confounding variables, residual confounding remains a possibility.

WIDER IMPLICATIONS OF THE FINDINGS

Inequitable burden of air pollution exposure has important implications for racial health disparities, and may be related to disparities in UL. Our results emphasize the need for additional research focused on environmental causes of UL.

STUDY FUNDING/COMPETING INTEREST(S)

This research was funded by the National Cancer Institute (U01-CAA164974) and the National Institute of Environmental Health Sciences (R01-ES019573). L.A.W. is a fibroid consultant for AbbVie, Inc. and accepts in-kind donations from Swiss Precision Diagnostics, Sandstone Diagnostics, FertilityFriend.com and Kindara.com for primary data collection in Pregnancy Study Online (PRESTO). M.J. declares consultancy fees from the Health Effects Institute (as a member of the review committee). The remaining authors declare they have no actual or potential competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Endometrial function in women with polycystic ovary syndrome: a comprehensive review

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility. An endometrial component has been suggested to contribute to subfertility and poor reproductive outcomes in affected women.

OBJECTIVE AND RATIONALE

The aim of this review was to determine whether there is sufficient evidence to support that endometrial function is altered in women with PCOS, whether clinical features of PCOS affect the endometrium, and whether there are evidence-based interventions to improve endometrial dysfunction in PCOS women.

SEARCH METHODS

An extensive literature search was performed from 1970 up to July 2020 using PubMed and Web of Science without language restriction. The search included all titles and abstracts assessing a relationship between PCOS and endometrial function, the role played by clinical and biochemical/hormonal factors related to PCOS and endometrial function, and the potential interventions aimed to improve endometrial function in women with PCOS. All published papers were included if considered relevant. Studies having a specific topic/hypothesis regarding endometrial cancer/hyperplasia in women with PCOS were excluded from the analysis.

OUTCOMES

Experimental and clinical data suggest that the endometrium differs in women with PCOS when compared to healthy controls. Clinical characteristics related to the syndrome, alone and/or in combination, may contribute to dysregulation of endometrial expression of sex hormone receptors and co-receptors, increase endometrial insulin-resistance with impaired glucose transport and utilization, and result in chronic low-grade inflammation, immune dysfunction, altered uterine vascularity, abnormal endometrial gene expression and cellular abnormalities in women with PCOS. Among several interventions to improve endometrial function in women with PCOS, to date, only lifestyle modification, metformin and bariatric surgery have the highest scientific evidence for clinical benefit.

WIDER IMPLICATIONS

Endometrial dysfunction and abnormal trophoblast invasion and placentation in PCOS women can predispose to miscarriage and pregnancy complications. Thus, patients and their health care providers should advise about these risks. Although currently no intervention can be universally recommended to reverse endometrial dysfunction in PCOS women, lifestyle modifications and metformin may improve underlying endometrial dysfunction and pregnancy outcomes in obese and/or insulin resistant patients. Bariatric surgery has shown its efficacy in severely obese PCOS patients, but a careful evaluation of the benefit/risk ratio is warranted. Large scale randomized controlled clinical trials should address these possibilities.

Determination of urinary carnitine levels as a potential indicator of uterine fibroids caused by nonylphenol exposure

Our previous studies have shown that uterine fibroids are associated with nonylphenol (NP) exposure, and the changes of carnitines in critical reproductive tissues and body fluids could be used to indicate the female reproductive toxicity caused by NP exposure. In this work, on the basis of further clarifying the correlation between NP exposure level and uterine fibroids, the possibility of the urinary carnitine levels as a potential indicator of uterine fibroids caused by NP exposure was discussed. The urine samples were collected from 84 female volunteers: the control group of 34 healthy women without gynecological disease and 50 uterine fibroids patients, respectively. Methods were respectively established for the determination of NP and eight carnitines in human urine samples by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The results showed that the NP level of uterine fibroids group was significantly higher than that of control group (P = 0.002), indicating that NP exposure was an important environmental factor in the occurrence of uterine fibroids. It was further found that in urine samples of the uterine fibroids group, the levels of L-Carnitine (C0), L-Acetyl-carnitine (C2), L-Octanoyl-carnitine (C8), Tetradecanoyl-carnitine (C14), Oleoyl-carnitine (C18:1) and Linoleoyl-carnitine (C18:2) had obviously increased compared with those in the control group (P < 0.001; < 0.001; < 0.001; = 0.003; < 0.001; = 0.010). The concentrations of L-Hexanoyl-carnitine (C6) and L-Palmitoyl-carnitine (C16) in the uterine fibroids group were also higher than those in the control group, although the difference was not statistically significant (P > 0.05). The results suggested that the changes in urinary carnitine levels might be a potential indicator to help to warn of the risk of uterine fibroids caused by NP exposure at the early stage.

Lower prevalence of non-cavity-distorting uterine fibroids in patients with polycystic ovary syndrome than in those with unexplained infertility

OBJECTIVE

To study whether there is a difference in the prevalence of non-cavity-distorting uterine fibroids between infertile patients with polycystic ovary syndrome (PCOS) and those with unexplained infertility (UI).

DESIGN

A secondary analysis of data from three randomized clinical trials.

SETTING

Academic health centers.

PATIENT(S)

A total of 2,249 patients with normal uterine cavities.

INTERVENTIONS(S)

None.

MAIN OUTCOME MEASURE(S)

The presence or absence of non-cavity-distorting fibroids.

RESULT(S)

Compared with women with UI, those with PCOS were younger, had a higher body mass index, and were more likely to be Hispanic or African American, with a lower percentage of previous conception and live birth, a higher percentage of current smokers, a lower percentage of current alcohol users, and higher total testosterone, fasting insulin, and homeostasis-model-assessment insulin resistance. The prevalence of women with non-cavity-distorting uterine fibroids was lower in women with PCOS than in those with UI (6.7% vs. 12.4%); this result held after patients were divided into Black and non-Black or into three different body mass index groups. After adjustment for all the other variables in the final model, patients with PCOS had a significantly lower prevalence of fibroids than those with UI (odds ratio 0.54). No differences in the prevalence of non-cavity-distorting fibroids with any dimensions ≥4 cm or the volume of the largest fibroid was found between the two groups.

CONCLUSION(S)

A lower prevalence of non-cavity-distorting uterine fibroids was found in infertile women with PCOS than in those with UI.

Assessment of oxidant-antioxidant status alterations with tumor biomarkers and reproductive system hormones in uterine MYOMAS

OBJECTIVES

Uterine myomas (UM) are responsible for significant morbidity and have adverse effects on quality of life in women. Reactive oxygen species (ROS) and antioxidant enzymes (AOE), as well as sex steroids play important roles in the reproductive physiology processes. Thus, we aimed to investigate the role of oxidant-antioxidant status in UM by measuring the AOE activities and lipid peroxidation (LPO) levels. This is the first study assessing these parameters together in UM based on also menopausal status and evaluating possible correlations between AOE activities, LPO markers, tumor biomarkers, female reproductive system hormone levels, comprehensively.

STUDY DESIGN

The study group consisted of patients who have undergone surgical resection with confirmed pathology of uterine myoma (UM, n = 25) and divided into subgroups; premenopausal (UM_pre) and postmenopausal (UM_post). Erythrocyte copper-zinc superoxide dismutase (Cu,Zn-SOD), catalase (CAT), glutathione peroxidase (GPx1) activities were measured along with plasma malondialdehyde (MDA) and urinary 8-epi-prostaglandin F2α (8-epi-PGF2α) levels in patients with UM. The obtained data were compared to the data of healthy individuals (C, n = 25) and its subgroups; premenopausal (C_pre) and postmenopausal (C_post).

RESULTS

All AOE activities were higher (∼40% for Cu,Zn-SOD, p = 0.003; ∼55% for CAT, p = 0.001; ∼15% for GPx1, p = 0.169) and the LPO levels were lower (∼60% for MDA, p = 0.011 and ∼45% for 8-epi-PGF2α, p = 0.055) in patients with UM vs control. Approximately similar alterations were observed in UM_pre vs C_pre and in UM_post vs C_post. A significant negative correlation between erythrocyte Cu,Zn-SOD activity and plasma MDA levels (r = -0.431, p = 0.005) was reported.

CONCLUSION

Decreased LPO levels might be the consequence of compensator high antioxidant enzyme activities against mild oxidative stress in the circulation of patients with UM. The marked negative correlation between erythrocyte Cu,Zn-SOD activity and plasma MDA levels also supported this finding.

Human Chorionic Gonadotrophin as a Possible Mediator of Leiomyoma Growth during Pregnancy: Molecular Mechanisms

Uterine fibroids are the most common gynecologic benign tumors. Studies supporting a strong pregnancy-related growth of leiomyomas generally claimed a crucial role of sex steroid hormones. However, sex steroids are unlikely the unique actors involved as estrogen and progesterone achieve a pick serum concentration in the last trimester while leiomyomas show a typical increase during the first trimester. Given the rapid exponential raise in serum human Chorionic Gonadotrophin (hCG) at the beginning of gestation, we conducted a review to assess the potential role of hCG in the striking growth of leiomyomas during initial pregnancy. Fibroid growth during initial pregnancy seems to correlate to the similar increase of serum hCG levels until 12 weeks of gestation. The presence of functional Luteinizing Hormone/human Chorionic Gonadotropin (LH/hCG) receptors was demonstrated on leiomyomas. In vitro treatment of leiomyoma cells with hCG determines an up to 500% increase in cell number after three days. Expression of cyclin E and cyclin-dependent kinase 1 was significantly increased in leiomyoma cells by hCG treatment. Moreover, upon binding to the receptor, hCG stimulates prolactin secretion in leiomyoma cells, promoting cell proliferation via the mitogen-activated protein kinase cascade. Fibroid enlargement during initial pregnancy may be regulated by serum hCG.

Epidemiology of Uterine Fibroids: From Menarche to Menopause

Uterine leiomyomata (UL) have a substantial impact on women's health, but relatively few studies have identified opportunities for primary prevention of these neoplasms. Most established risk factors are not modifiable, including premenopausal age, African ancestry, age at menarche, and childbearing history. The main challenge in studying UL is that a large proportion of tumors are asymptomatic. Herein, we review the epidemiology of UL from published studies to date. We highlight the advantages of ultrasound screening studies and the ways in which their innovative methods have helped clarify the etiology of disease. We conclude with a discussion of promising new hypotheses.

Induced and Spontaneous Abortion and Risk of Uterine Fibroids

BACKGROUND

The relationship between abortion and uterine fibroids has received little attention. The aim of the present study was to explore the association between number of induced and spontaneous abortions and the risk of uterine fibroids in middle-aged and older Chinese women.

METHODS

A total of 14,595 retired female employees from the Dongfeng-Tongji cohort study were included in our analysis. Information on induced and spontaneous abortions was collected by trained interviewers through face-to-face interviews. Diagnosis of uterine fibroids was based on ultrasound or self-reported physician diagnosis of uterine fibroids. Logistic regression models were used to explore the associations between number of induced and spontaneous abortions and the risk of uterine fibroids.

RESULTS

The prevalence of uterine fibroids was 15.1% among all participants. Higher number of induced abortions was associated with an increased risk of uterine fibroids (1 induced abortion: odds ratios [ORs] = 1.32, 95% confidence interval [CI] 1.18-1.48; 2 induced abortions: OR = 1.45, 95% CI 1.28-1.64; and ≥3 induced abortions: OR = 1.62, 95% CI 1.39-1.90). Compared with women without induced abortion, ORs for women with 1, 2, and ≥3 were 1.17 (95% CI 1.03-1.32), 1.21 (95% CI 1.06-1.39), and 1.36 (95% CI 1.15-1.61), respectively, after adjustment for potential confounders. No association was observed between the number of spontaneous abortions and the risk of uterine fibroids.

CONCLUSION

The findings of this study showed that induced abortion may be an independent risk factor for uterine fibroids in middle-aged and older Chinese women.

Circulating Sex Hormones and Risk of Uterine Fibroids: Study of Women's Health Across the Nation (SWAN)

CONTEXT

Estrogen has been implicated in the development of uterine fibroids. However, the contribution of androgen in women is unknown.

OBJECTIVE

Our objective was to assess the longitudinal relations of circulating androgens and estradiol (E2) and their joint effects to the risk of developing fibroids.

DESIGN

This is a 13-year longitudinal study in the Study of Women's Health Across the Nation.

SETTING

This study was conducted in seven sites across the United States (1997-2013).

PARTICIPANTS

At baseline, 3240 pre- or early peri-menopausal women with an intact uterus, ages 45-52 years were included; 43.6% completed the follow-up. There were 512 incident and 478 recurrent fibroid cases.

EXPOSURES

We measured near-annual time-varying serum levels of bioavailable E2 and bioavailable T, dichotomized at the median (high vs low).

MAIN OUTCOMES AND MEASURES

We estimated the conditional odds ratio (OR) of fibroids in the ensuing year using discrete-time proportional odds models adjusted for race/ethnicity/site, age, body mass index, menopausal stage, reproductive factors, smoking, timing of blood draw, and FSH.

RESULTS

Women with high T had a statistically significant increased risk of incident fibroids (OR, 1.33; 95% confidence interval [CI], 1.01-1.76; P = .04), but not recurrent fibroids. This risk was further elevated in those with high T and E2 (OR, 1.52; 95% CI, 1.07-2.17; P = .02). High E2 and T was associated with lower risk of recurrent fibroids (OR, 0.50; 95% CI, 0.26-0.96; P = .04).

CONCLUSIONS

High T with high E2 was associated with an elevated risk of incident fibroids in midlife women who never reported fibroids before baseline. Conversely, the risk of recurrent fibroids was mitigated in women with high E2 and high T.

Current understanding of somatic stem cells in leiomyoma formation

OBJECTIVE

To provide a detailed summary of current scientific knowledge of somatic stem cells (SSCs) in murine and human myometrium and their putative implication in leiomyoma formation, as well as to establish new therapeutic options.

DESIGN

Pubmed and Scholar One manuscripts were used to identify the most relevant studies on SSCs and their implications in human myometrium and leiomyomas.

SETTING

University research laboratory-affiliated infertility clinic.

PATIENT(S)

Not applicable.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Not applicable.

RESULT(S)

Despite numerous publications on SSCs, it was not until 2007 that scientific evidence based on the use of 5-bromo-2'-deoxyuridine (BrdU) and side population (SP) methods in murine and human myometrium were first published. Recently, it has been reported that SP cells are present in human leiomyomas; however, to date the pathogenesis of this benign tumor remains unclear. Besides many genetic/epigenetic alterations, changes to steroid hormones and growth factors may also be associated with the impaired function, proliferation, and differentiation of a subset of putative SSCs in human myometrium.

CONCLUSION(S)

These findings open up new possibilities for understanding the origin of this benign tumor and help to develop new nonsurgical approaches for their management.

Uterine fibroids: current perspectives

Uterine fibroids are a major cause of morbidity in women of a reproductive age (and sometimes even after menopause). There are several factors that are attributed to underlie the development and incidence of these common tumors, but this further corroborates their relatively unknown etiology. The most likely presentation of fibroids is by their effect on the woman's menstrual cycle or pelvic pressure symptoms. Leiomyosarcoma is a very rare entity that should be suspected in postmenopausal women with fibroid growth (and no concurrent hormone replacement therapy). The gold standard diagnostic modality for uterine fibroids appears to be gray-scale ultrasonography, with magnetic resonance imaging being a close second option in complex clinical circumstances. The management of uterine fibroids can be approached medically, surgically, and even by minimal access techniques. The recent introduction of selective progesterone receptor modulators (SPRMs) and aromatase inhibitors has added more armamentarium to the medical options of treatment. Uterine artery embolization (UAE) has now been well-recognized as a uterine-sparing (fertility-preserving) method of treating fibroids. More recently, the introduction of ultrasound waves (MRgFUS) or radiofrequency (VizAblate™ and Acessa™) for uterine fibroid ablation has added to the options of minimal access treatment. More definite surgery in the form of myomectomy or hysterectomy can be performed via the minimal access or open route methods. Our article seeks to review the already established information on uterine fibroids with added emphasis on contemporary knowledge.

The rapid growth of fibroids during early pregnancy

Several studies aimed to disentangle whether pregnancy influences the growth of uterine fibroids but results were inconsistent. In this study, we speculated that fibroid enlargement during pregnancy may not be linear and we hypothesized that this phenomenon may mainly occur during initial pregnancy. To test this hypothesis, we set up a prospective cohort study of women with fibroids undergoing IVF. Cases were women achieving a viable pregnancy. Controls were the subsequent women with fibroids but failing to become pregnant. Twenty-five cases and 25 controls were recruited. The total number of fibroids in the two groups was 46 and 41, respectively. The mean ± SD diameter of the fibroids was 17±10 and 20±11 mm, respectively (p = 0.18). A statistically significant enlargement emerged exclusively in pregnant women. The median (Interquartile Range) modification of the diameter of the lesions in cases and controls was +34% (+6%/+65%) and +2% (−6%/+12%), respectively (p<0.001). The median (Interquartile Range) modification of the volume of the lesions was +140% (+23%/+357%) and 0% (−18%/+37%), respectively (p<0.001). In pregnant women, we failed to document any significant correlation between the magnitude of the growth and ovarian responsiveness to hyper-stimulation, suggesting that steroids hormones are not the unique factors involved. In conclusion, fibroids undergo a rapid and remarkable growth during initial pregnancy. Reasons behind this phenomenon remain to be clarified. The early rise in steroids hormones during early pregnancy may not be sufficient to explain the process. Other pregnancy-related hormones and proteins may play also key roles.

Self-Reported Daily Stress, Squelching of Anger and the Management of Daily Stress and the Prevalence of Uterine Leiomyomata: The Ultrasound Screening Study

Self-reported daily stress, ways of managing stress and squelching anger were examined in association with uterine leiomyomata (aka fibroids). These stress factors were obtained from 560 Black and 375 White women enrolled in the National Institute of Environmental Health Sciences Uterine Fibroid Study. Race-specific prevalence differences (PD) and 95% confidence intervals (95% CI) were calculated. Black women with severe stress had a prevalence of fibroids that was 11% higher (95% CI: 0%, 21%) than those in the no or mild stress group (referent). White women with severe stress, compared to the referent, had a non-significantly (NS) higher prevalence of fibroids [PD = 7%; 95% CI: (-103, 213)]. For both groups, moderate daily stress was associated with a weak elevation (NS) in fibroid prevalence. Black women who reported squelching their anger had an elevated prevalence of fibroids (8%) compared to non-squelchers [95% CI: (-03, 153)] while there was no association for White women. Women with symptomatic fibroids had higher stress than those without, but exclusion of symptomatic women only slightly attenuated the associations. Consistent with a previous report, symptomatic fibroids may cause stress. However, further research is warranted to prospectively investigate a possible aetiologic role for stress in the development of fibroids.

New directions in the epidemiology of uterine fibroids

Although uterine leiomyomata (fibroids) have been the leading indication for hysterectomy in the United States for decades, the epidemiological data on fibroid prevalence and risk factors are limited. Given the hormonal dependence of fibroids, most earlier studies focused on reproductive or hormonal factors. Recent analyses have extended that focus to other areas. We present previously unpublished data on the association between reproductive tract infections and fibroids that highlight the need for more detailed studies. Our review suggests that metabolic, dietary, stress, and environmental factors may also play a role in fibroid development.

Endometrial responses to embryonic signals in the primate

The delicate interaction between an embryo and the uterus to initiate implantation and maintain pregnancy is one of the most elegant and fascinating interactions in human biology. Understanding the molecular events of embryo-maternal interaction is of interest to reproductive biologists, clinicians and couples affected by infertility. We have established the baboon as the non-human primate model for studying embryo implantation. Infusion of chorionic gonadotropin (CG), the major embryonic signal of primates, into the uterine cavity of normal cycling baboons during the window of receptivity induces a myriad of morphological, biochemical and molecular changes in the estrogen and progesterone primed endometrium. The luminal epithelium responds by forming plaques, the overall secretory function of the glandular epithelium increases and the stromal response is characterized by induction of alpha-smooth muscle actin (alphaSMA). Cross talk between ovarian and embryonic hormones is evidenced by the fact that these responses are inhibited upon treatment with a progesterone receptor antagonist. CG signals principally through the seven transmembrane LH/CG G-protein coupled receptor, and activates a mitogen activated protein kinase pathway in the endometrial epithelium that is unique and independent of all the classical signaling pathways. In the stromal compartment, CG both rescues stromal fibroblasts from their apoptotic demise and also differentiates them into the decidualized phenotype. We propose that stromal cell survival and differentiation is mediated by a critical modulator of cell fate, Notch-1. Thus, CG is an important embryonic signal which modulates communication between the embryo and the endometrium and induces changes that are critical to successful implantation.

Mother's menopausal age is associated with her daughter's early follicular phase urinary follicle-stimulating hormone level

OBJECTIVE

Early follicular phase follicle-stimulating hormone (FSH), a marker of ovarian reserve, has been used to predict time to menopause. A mother's age at menopause is related to her daughter's age at menopause, possibly because of genetic factors. In this study we sought to determine the relationship between maternal age at menopause and early follicular phase FSH of premenopausal daughters.

DESIGN

The Uterine Fibroid Study enrolled women randomly selected from a prepaid health plan, collected questionnaire data, and obtained early follicular phase urine samples for a subset of participants. For this secondary analysis, premenopausal women between the ages of 35 and 46 years, who provided a urine sample on cycle day 2, 3, 4, or 5 and their mother's age at natural menopause (n = 182) were selected from the original cohort. Initially bivariate analysis and subsequently regression modeling were performed to assess the independent relationship between maternal age at menopause and urinary creatinine-corrected FSH.

RESULTS

Unadjusted analyses and those adjusting for age (mean +/- SD, 40.5 +/- 3.2 y), smoking status (16% current smokers), and body mass index (26.8 +/- 6.9 kg/m) showed a significant association between maternal age at menopause and daughter's urinary FSH level (P < 0.04). Women whose mothers experienced earlier menopause had higher urinary FSH levels.

CONCLUSIONS

The significantly increased FSH values among women whose mothers experienced early menopause is consistent with previously reported associations between mother's and daughter's age of menopause. FSH, a marker of ovarian reserve, is influenced by both genetic and environmental factors. Future epidemiologic studies on FSH should include collection of information on maternal age at menopause.

Incidence, aetiology and epidemiology of uterine fibroids

Uterine fibroids are the most common benign tumour of the female genital tract. However, their true prevalence is probably under-estimated, as the incidence at histology is more than double the clinical incidence. Recent longitudinal studies have estimated that the lifetime risk of fibroids in a woman over the age of 45 years is more than 60%, with incidence higher in blacks than in whites. The cause of fibroids remains unclear and their biology poorly understood. No single candidate gene has been detected for commonly occurring uterine fibroids. However, the occurrence of rare uterine fibroid syndromes, such as multiple cutaneous and uterine leiomyomatosis, has been traced to the gene that codes for the mitochondrial enzyme, fumarate hydratase. Cytogenetic abnormalities, particularly deletions of chromosome 7, which are found in up to 50% of fibroid specimens, seem to be secondary rather than primary events, and investigations into the role of tumour suppressor genes have yielded conflicting results. The key regulators of fibroid growth are ovarian steroids, both oestrogen and progestogen, growth factors and angiogenesis, and the process of apoptosis. Black race, heredity, nulliparity, obesity, polycystic ovary syndrome, diabetes and hypertension are associated with increased risk of fibroids, and there is emerging evidence that familial predisposition to fibroids is associated with a distinct pattern of clinical and molecular features compared with fibroids in families without this prevalence.

Polycystic ovary syndrome and risk of uterine leiomyomata

OBJECTIVE

To examine the association between polycystic ovary syndrome (PCOS) and the risk of uterine leiomyomata (UL).

DESIGN

Prospective cohort study.

SETTING

Participants from the Black Women's Health Study, an ongoing prospective cohort study of African-American women aged 21-69 years in 1995 residing in the United States. Participants completed mailed questionnaires about their health status every 2 years.

PATIENT(S)

Premenopausal women with no history of UL at the start of follow-up (N = 23,571).

INTERVENTION(S)

No interventions were administered.

MAIN OUTCOME MEASURE

Incidence of UL among those with and without self-reported, physician-diagnosed PCOS over a 6-year period of follow-up (1997-2003). Medical-record validation in a random subset of UL cases confirmed 96% of diagnoses.

RESULT(S)

During 114,373 person-years of follow-up, 3,631 new cases of UL confirmed by ultrasound (N = 2,926) or hysterectomy (N = 705) were reported. After adjustment for potential confounders, the incidence of UL was 65% higher among women with PCOS than women without PCOS (incidence rate ratio, 1.65; 95% confidence interval, 1.21-2.24). The incidence rate ratios remained constant with increasing time after the diagnosis of PCOS. Results were similar when analyses were confined to women reporting a recent Papanicolaou smear, a proxy for a pelvic examination.

CONCLUSION(S)

The present study suggests a positive association between PCOS and UL in African-American women.