Psychological stress is related to a decrease of serum anti-müllerian hormone level in infertile women

Vitamin D deficiency, insulin resistance, and antimüllerian hormone level: a tale of trio in the expression of polycystic ovary syndrome

OBJECTIVE

To study the association between altered vitamin D profiles and different indices as well as clinical features of polycystic ovary syndrome (PCOS), including antimüllerian hormone (AMH) levels, phenotypes (A [hyperandrogenism {HA} + ovulatory dysfunction {OD} + polycystic ovarian morphology {PCOM}], B [HA + OD], C [HA + PCOM], and D [OD + PCOM]), insulin resistance, oligomenorrhea, hyperandrogenism, obesity indices, and stress biomarkers in the ethnic population of West Bengal.

DESIGN

Case-control observational study.

SETTING

Outpatient department of gynecology and obstetrics and environing.

PARTICIPANTS (PATIENTS AND CONTROL)

Sample size: case group (PCOS, n = 160), age: 16-38 years, and their gender, age, as well as ethnicity-matched healthy control (n = 160).

INTERVENTION(S)

In this observational study, a structured questionnaire for menstrual status and to determine the scores of cutaneous manifestations, a bioelectrical impedance analyzer for measurement of anthropometric indices, relevant biochemical assessments (vitamin D, AMH, insulin, glucose, and other associated hormonal profiles), statistical software for the social sciences, and Microsoft Office Excel were used to evaluate as well as analyze different indices.

MAIN OUTCOME MEASURE(S)

Study of the association of vitamin D deficiency with differential manifestations of PCOS such as phenotypes of the syndrome, altered AMH levels, and risk of insulin resistance. An attempt has been made to determine the cutoff value of AMH of the patients with PCOS belonging to the ethnic population of West Bengal using receiver operating characteristic (ROC).

RESULT(S)

Vitamin D deficiency was found to be directly correlated with AMH level in PCOS phenotype A (67%), oligomenorrhea, and PCOM, along with a substantial agonistic relationship with insulin resistance in the PCOS population under study. In the PCOS phenotype B, the AMH level was highest, with a cutoff value of 5.27 ng/mL (asymptotic sig. = 0.000, 95% confidence interval: 8.37-9.95, derived by ROC analysis, with area under the ROC curve- area under the curve value = 0.949, sensitivity=0.882, and specificity = 0.880). Oligomenorrhic women with PCOS possess significantly higher values of AMH levels (8.70 ± 3.66 > 3.09 ± 1.86 ng/mL) level than the regular menstrual rhythm within the same group. Patients with PCOS had significantly less skeletal muscle mass and greater subcutaneous fat content than the control group.

CONCLUSION(S)

25-hydroxy-vitamin D might be intermeshed with the underlying pathophysiology and severity of PCOS, as well as associated metabolic disorders like insulin resistance. The AMH level is finely tuned by most of the plausible effectors of PCOS and contends to be a promising biomarker for the diagnosis as well as prognosis of PCOS.

Potential factors result in diminished ovarian reserve: a comprehensive review

The ovarian reserve is defined as the quantity of oocytes stored in the ovary or the number of oocytes that can be recruited. Ovarian reserve can be affected by many factors, including hormones, metabolites, initial ovarian reserve, environmental problems, diseases, and medications, among others. With the trend of postponing of pregnancy in modern society, diminished ovarian reserve (DOR) has become one of the most common challenges in current clinical reproductive medicine. Attributed to its unclear mechanism and complex clinical features, it is difficult for physicians to administer targeted treatment. This review focuses on the factors associated with ovarian reserve and discusses the potential influences and pathogenic factors that may explain the possible mechanisms of DOR, which can be improved or built upon by subsequent researchers to verify, replicate, and establish further study findings, as well as for scientists to find new treatments.

Perceived stress and markers of ovarian reserve among subfertile women

RESEARCH QUESTION

Is self-reported psychological stress associated with markers of ovarian reserve among subfertile women?

DESIGN

Observational study of women (n = 520) seeking fertility care at the Massachusetts General Hospital who enrolled in the Environment and Reproductive Health study between 2005 and 2019. Women completed the short version of the validated PSS4, which assesses psychological stress. Ovarian reserve markers included AFC and circulating serum levels of day-3 FSH, with AMH assessed in a subset of participants (n = 185).

RESULTS

Higher total PSS4 scores were negatively associated with AFC and serum AMH levels. Analyses adjusted for age, BMI, race, smoking, education, physical activity and type of infertility diagnosis. Women in the second and third tertiles of stress had lower AFC (13.3, 95% CI 12.7 to 13.8; and 13.5, 95% CI 13.0 to 14.1) compared with women in the lowest tertile of psychological stress score (14.3, 95% CI 13.8 to 14.9, both P < 0.05). Women in the second and third tertiles of total PSS4 scores also had lower mean serum AMH compared with women in the lowest tertile (2.99, 95% CI 2.24 to 3.74), and (2.99 95% CI 2.22 to 3.76) versus (3.94 95% CI 3.23 to 4.64). These associations varied by several socioeconomic factors, and were observed among women who were younger, belonging to minority races, with a college degree or with annual household income less than $100,000.

CONCLUSIONS

Higher perceived stress was negatively associated with AFC and serum AMH levels. These associations varied by several socioeconomic factors.

High Housing Density-Induced Chronic Stress Diminishes Ovarian Reserve via Granulosa Cell Apoptosis by Angiotensin II Overexpression in Mice

Repeated and prolonged stress causes hypothalamic-pituitary-adrenal (HPA) dysregulation. Excessive hypothalamic-pituitary-adrenal axis activity has been linked to inadequate activation of the hypothalamus-pituitary-ovarian axis, which controls the growth and development of ovarian follicles and oocytes. Therefore, we assessed the ovarian reserve under high-housing-density-induced prolonged stress, and investigated the mechanisms underlying diminished ovarian reserve in this study. Eight-week-old female C57BL/6 mice were housed for 10 weeks under different housing densities. We then assessed hormone levels, performed histology and immunohistochemistry analyses of ovarian follicles, evaluated ovarian mRNA expression, and measured angiotensin II-mediated apoptosis in vitro. More densely housed mice presented increased corticosterone levels and decreased follicle-stimulating and luteinizing hormone levels. Moreover, mice exposed to prolonged ordinary stress showed a reduced level of serum anti-Müllerian hormone and an increased number of atretic ovarian follicles. Stressed mice showed increased levels of angiotensinogen and angiotensin II in the ovaries and serum. Furthermore, our in vitro study confirmed that high-housing-density-related stress induced granulosa cell apoptosis, resulting in diminished ovarian reserves. Collectively, our findings highlight the importance of women managing everyday stress to maintain their reproductive health.

Anti-Müllerian Hormone Levels among Female Firefighters

Female firefighters have occupational exposures which may negatively impact their reproductive health. Anti-müllerian hormone (AMH) is a clinical marker of ovarian reserve. We investigated whether AMH levels differed in female firefighters compared to non-firefighters and whether there was a dose-dependent relationship between years of firefighting and AMH levels. Female firefighters from a pre-existing cohort completed a cross-sectional survey regarding their occupational and health history and were asked to recruit a non-firefighter friend or relative. All participants provided a dried blood spot (DBS) for AMH analysis. Linear regression was used to assess the relationship between firefighting status and AMH levels. Among firefighters, the influence of firefighting-related exposures was evaluated. Firefighters (n = 106) and non-firefighters (n = 58) had similar age and BMI. Firefighters had a lower mean AMH compared to non-firefighters (2.93 ng/mL vs. 4.37 ng/mL). In multivariable adjusted models, firefighters had a 33% lower AMH value than non-firefighters (-33.38%∆ (95% CI: -54.97, -1.43)). Years of firefighting was not associated with a decrease in AMH. Firefighters in this study had lower AMH levels than non-firefighters. More research is needed to understand the mechanisms by which firefighting could reduce AMH and affect fertility.

Investigating the Clinical Utility of the Anti-Mullerian Hormone Testing for the Prediction of Age at Menopause and Assessment of Functional Ovarian Reserve: A Practical Approach and Recent Updates

Low ovarian reserve is a serious condition, leading to sterility in up to 10% of women in their mid-thirties. According to current knowledge, serum anti-Müllerian hormone (AMH) levels for age are the best available marker for the screening the quantity of a woman's functional ovarian reserve, better than age alone or other reproductive markers. This review summarizes recent findings, clinical utility and limitations in the application of serum AMH testing as an accurate marker for the screening of functional ovarian reserves and predicting age at menopause. AMH assessment hold promise in helping women make informed decisions about their future fertility and desired family size. However, screening of the functional ovarian reserve could be offered to all women at 26 years of age or older who seek to assess future fertility or in case of personal request, ovarian reserve screening may be considered beyond 30 years; however, it has never been advocated beyond 35 years, since it is not advisable to delay childbearing beyond this age. In this respect, an age-specific serum AMH levels lower than the 10th percentile may be used as a threshold for the identification of a low functional ovarian reserve in an individual woman. Its level should be interpreted with caution in the adolescent and young women aged below 25 years (since AMH levels peak at this age); recent users of hormonal contraceptives (since AMH levels transiently decrease until two months after discontinuation); and women with PCOS (which dramatically increases AMH levels). However, the ability of AMH levels to predict the time to menopause is promising but requires further investigation and routine AMH testing for the purposes of predicting the time to menopause is not recommended.

Chronic and Cumulative Adverse Life Events in Women with Primary Ovarian Insufficiency: An Exploratory Qualitative Study

BACKGROUND AND PURPOSE

Primary ovarian insufficiency (POI) has serious physical and psychological consequences due to estradiol deprivation, leading to increased morbidity and mortality. However, the causes of most POI cases remain unknown. Psychological stress, usually caused by stressful life events, is known to be negatively associated with ovarian function. It is important to explore high-frequency adverse life events among women with POI for future interventions.

METHODS

Forty-three women (mean age=33·8 years) were recruited who were newly- diagnosed with idiopathic POI (FSH levels >40 IU/L) to participate in semi-structured interviews through convenience sampling. The main questions covered by the topic guide were designed to explore adverse life events prior to POI diagnosis. Interviews were audio recorded, transcribed and analyzed thematically. Data were analyzed from June 2019 to August 2020.

RESULTS

Among the women with POI, mean age at diagnosis of POI was 33·8 years (range from 19 to 39 years), and the average time between the onset of irregular menstruation and POI diagnosis was 2.3 years. These women with POI had a relatively normal menstrual cycle before the diagnosis. A number of stressful life events prior to POI diagnosis were discussed by them as important factors influencing their health. Four core themes emerged: 1) persistent exposure to workplace stress, 2) persistent exposure to family-related adverse life events, 3) sleep problem/disturbance existed in women with POI before diagnosis, and 4) participants' general cognition and concerns about POI.

CONCLUSIONS

Persistent exposures to adverse life events related to work stress, family stress and sleep problem existed in women with POI. Our findings are consistent with the hypothesis that adverse life events play a role in the development of POI. Future research should investigate how social environmental factors influence POI disease risks, and whether provision of tailored interventions (i.e. preventing or mitigating impact of adverse life events) aimed at high-risk populations may help prevent new POI cases and improve conditions of women with POI. We gained an in-depth understanding of the experiences of these women via 1:1 qualitative method, and find adverse life events are frequent in women with POI prior to the diagnosis.

Low Anti-Mullerian Hormone Levels Are Associated with the Severity of Anxiety Experienced by Healthcare Professionals During the COVID-19 Pandemic

The objective of this study is to investigate a possible correlation between anxiety status and anti-Mullerian hormone (AMH) levels among healthcare professionals who provide medical care directly to COVID-19-positive patients during the recent pandemic. Fifty-two healthcare professionals (nurses, midwives, and residents) who provide medical care directly to COVID-19-positive patients in inpatient clinics or intensive care units were enrolled in this study. Serum AMH levels were analyzed to reflect ovarian reserve. The Beck Anxiety Inventory (BAI) and the State-Trait Anxiety Inventory (STAI-S and STAI-T, respectively) were completed by participants to assess their anxiety status. A linear regression model with participant age as the constant variable was applied to analyze the relationship between inventory scale scores and AMH levels. P-values less than 0.05 were considered statistically significant. The mean AMH value was significantly lower for the participants in the moderate/severe anxiety group compared to the minimal/mild anxiety group (p = 0.007). A linear regression analysis revealed a significant negative correlation between AMH levels and both BAI (B = -0.030, standard error = 0.010, p = 0.004) and STAI-S and STAI-T scores when age was controlled (both p = 0.003). The severity of anxiety experienced during the recent COVID-19 pandemic among healthcare professionals, who provide medical care directly to COVID-19-positive patients, is found to be related to low AMH levels.

Menopause, anti-Müllerian hormone and cognition in a cohort of women with persistent symptoms following TBI: a case for future research

Objectives: Primary: To explore anti-Müllerian Hormone (AMH) levels in community dwelling women following TBI. Secondary: To explore the relation of AMH to menstrual cycle, cognition, distress and symptoms of menopause.Setting: Large adult TBI outpatient clinic in Toronto Canada.Research design: Prospective study of 10 women with persistent symptoms who were one or more years post TBI.Methods: Consenting participants provided a serum sample for AMH levels, and completed the Menopause Rating Scale (MRS), Symptom Checklist-90 r (SCL-90 r), Repeatable Battery for the Assessment of Neurological Status (RBANS) and a health questionnaire.Main outcomes and results: This study found lower than expected levels of AMH in 50% of participants relative to age matched norms and 50% of participants experienced new onset of menstrual changes. Also notable were findings of lower-than-expected cognitive scores in women over 35 and reports of menopause-related symptoms across all ages groups.Conclusions: As our understanding of the role of AMH grows, examining changes in this novel biomarker in the long-term post-TBI is warranted. Future research should be sufficiently powered to expand on and validate the study's findings.

The Effect of Free Androgen Index on the Quality of Life of Women With Polycystic Ovary Syndrome: A Cross-Sectional Study

Purpose: Free androgen index (FAI) and anti-Mullerian hormone (AMH) are independently associated with polycystic ovary syndrome (PCOS). This study aimed to describe the relationship between these two markers and health-related quality of life (HR-QoL) in women with PCOS. Methods: This cross-sectional study consisted of 81 women in the Hull PCOS biobank, who fulfilled the Rotterdam consensus criteria for the diagnosis of PCOS. The primary outcome was to measure the various domains of the QoL in the modified polycystic ovary syndrome questionnaire (MPCOSQ). Results: Mean age of the study participants was 28 ± 6.0 years, mean body mass index (BMI) 33.5 ± 7.8 kg/m², mean FAI (6 ± 5.5), free testosterone (2.99 ± 0.75) and mean AMH (3.5 ± 0.8 units). In linear regression analysis, the FAI was associated with overall mean MPCOSQ score (Beta = 0.53, P-value = 0.0002), and with depression (Beta = 0.45, P-value = 0.01), hirsutism (Beta = 0.99, P-value = 0.0002) and menstrual irregularity (Beta = 0.31, P-value = 0.04). However, with adjustment for age and BMI, FAI was only associated with the hirsutism domain (Beta = 0.94, P-value = 0.001) of the MPCOSQ. FAI was also associated with the weight domain (Beta = 0.63 P-value = 0.005) of MPCOSQ. However, AMH was not associated with the overall mean MPCOSQ score or with any of its domains. Conclusion: FAI but not AMH was associated with QoL in women with PCOS, and this effect was mediated by BMI.

Melatonin: Multi-Target Mechanism Against Diminished Ovarian Reserve Based on Network Pharmacology

BACKGROUND

Diminished ovarian reserve (DOR) significantly increases the risk of female infertility and contributes to reproductive technology failure. Recently, the role of melatonin in improving ovarian reserve (OR) has attracted widespread attention. However, details on the pharmacological targets and mechanisms of melatonin-improved OR remain unclear.

OBJECTIVE

A systems pharmacology strategy was proposed to elucidate the potential therapeutic mechanism of melatonin on DOR at the molecular, pathway, and network levels.

METHODS

The systems pharmacological approach consisted of target identification, data integration, network construction, bioinformatics analysis, and molecular docking.

RESULTS

From the molecular perspective, 26 potential therapeutic targets were identified. They participate in biological processes related to DOR development, such as reproductive structure development, epithelial cell proliferation, extrinsic apoptotic signaling pathway, PI3K signaling, among others. Eight hub targets (MAPK1, AKT1, EGFR, HRAS, SRC, ESR1, AR, and ALB) were identified. From the pathway level, 17 significant pathways, including the PI3K-Akt signaling pathway and the estrogen signaling pathway, were identified. In addition, the 17 signaling pathways interacted with the 26 potential therapeutic targets to form 4 functional modules. From the network point of view, by regulating five target subnetworks (aging, cell growth and death, development and regeneration, endocrine and immune systems), melatonin could exhibit anti-aging, anti-apoptosis, endocrine, and immune system regulation effects. The molecular docking results showed that melatonin bound well to all hub targets.

CONCLUSION

This study systematically and intuitively illustrated the possible pharmacological mechanisms of OR improvement by melatonin through anti-aging, anti-apoptosis, endocrine, and immune system regulation effects.

Polycystic Ovary Syndrome: A Brain Disorder Characterized by Eating Problems Originating during Puberty and Adolescence

Polycystic ovary syndrome (PCOS) is an endocrine condition associated with reproductive and psychiatric disorders, and with obesity. Eating disorders, such as bulimia and recurrent dieting, are also linked to PCOS. They can lead to the epigenetic dysregulation of the hypothalamic-pituitary-gonadal (HPG) axis, thereby impacting on ovarian folliculogenesis. We postulate that PCOS is induced by psychological distress and episodes of overeating and/or dieting during puberty and adolescence, when body dissatisfaction and emotional distress are often present. We propose that upregulated activation of the central HPG axis during this period can be epigenetically altered by psychological stressors and by bulimia/recurrent dieting, which are common during adolescence and which can lead to PCOS. This hypothesis is based on events that occur during a largely neglected stage of female reproductive development. To date, most research into the origins of PCOS has focused on the prenatal induction of this disorder, particularly in utero androgenization and the role of anti-Müllerian hormone. Establishing causality in our peripubertal model requires prospective cohort studies from infancy. Mechanistic studies should consider the role of the gut microbiota in addition to the epigenetic regulation of (neuro) hormones. Finally, clinicians should consider the importance of underlying chronic psychological distress and eating disorders in PCOS.

Diminished Ovarian Reserve in Girls and Adolescents with Trisomy X Syndrome

An extra X chromosome occurs in ~ 1 in 1000 females, resulting in a karyotype 47,XXX also known as trisomy X syndrome (TXS). Women with TXS appear to be at increased risk for premature ovarian insufficiency; however, very little research on this relationship has been conducted. The objective of this case-control study is to compare ovarian function, as measured by anti-mullerian hormone (AMH) levels, between girls with TXS and controls. Serum AMH concentrations were compared between 15 females with TXS (median age 13.4 years) and 26 controls (median age 15.1 years). Females with TXS had significantly lower serum AMH compared to controls (0.7 ng/mL (IQR 0.2-1.7) vs 2.7 (IQR 1.3-4.8), p < 0.001). Additionally, girls with TXS were much more likely to have an AMH below the 2.5th percentile for age with 67% of them meeting these criteria (OR 11, 95% CI 2.3-42). Lower AMH concentrations in females with TXS may represent an increased risk for primary ovarian insufficiency in these patients and potentially a narrow window of opportunity to pursue fertility preservation options. Additional research is needed to understand the natural history of low AMH concentrations and future risk of premature ovarian insufficiency in girls with TXS.

Association between a history of depression and anti-müllerian hormone among late-reproductive aged women: the Harvard study of moods and cycles

Background

There is conflicting evidence regarding the association between a history of depression and risk of early menopause. In a cohort of premenopausal women, we investigated the association between depression history and ovarian reserve, as measured by anti-müllerian hormone (AMH).

Methods

The Harvard Study of Moods and Cycles (HSMC) was a prospective cohort study of women living in the Boston, MA metropolitan-area (1995–1999). Women aged 36–45 years at cohort entry (1995) were sampled from seven Boston metropolitan-area communities using census directories. We measured serum AMH in early-follicular phase venous blood specimens from 141 women with a Structured Clinical Interview for DSM-IV (SCID)-confirmed history of depression and 228 without such a history. We calculated prevalence ratios (PR) for the association between characteristics of depression history and low AMH (≤1.4 ng/mL), adjusting for several potential confounders.

Results

The prevalence of low AMH was similar among depressed (57.5%) and non-depressed (57.9%) women (Adjusted [Adj] PR = 0.90, 95% CI: 0.75, 1.08). Among depressed women, results were not appreciably different among those who had ever used antidepressants and those with comorbid anxiety. Modest inverse associations between depression and low AMH were seen among women aged 36–40 years (Adj PR = 0.75, 95% CI: 0.52, 1.09) and nulliparous women (Adj PR = 0.77, 95% CI: 0.59, 1.00). No dose-response association with greater duration or length of depressive symptoms was observed.

Conclusions

Overall, the prevalence of low AMH was similar for depressed and non-depressed women 36–45 years of age. Surprisingly, among younger and nulliparous women, those with a history of depression had a slightly reduced prevalence of low AMH relative to those without such a history. These results do not indicate reduced ovarian reserve among women with a history of depression.

Perceived stress, psychological distress and serum anti-Müllerian hormone levels among infertile and fertile women in North-central Nigeria

Background

Previous studies reported that self-reported stress, stressful life events, and psychological distress influence ovarian ageing and response. However, there are limited, yet conflicting findings on the effect of stress and psychological distress on serum anti-Müllerian hormone (AMH) as a biomarker of ovarian reserve, response, and ageing. This case-control study aimed to determine if stress and psychological distress levels were associated with serum anti-Müllerian hormone levels among 81 infertile and 109 fertile women of reproductive age attending the gynaecology and immunization clinics of a tertiary hospital in North-central Nigeria, respectively. Stress and psychological distress were measured using the Perceived Stress scale-10 and Kessler Psychological Distress Scale-10, respectively. The serum concentration of AMH was determined using enzyme-linked immunosorbent assays.

Results

There was a significantly higher stress (p = 0.001) and psychological distress (p = 0.005) levels among infertile women; however, there was no difference in serum anti-Müllerian hormone levels between the two groups (p = 0.409). There was no significant correlation found between perceived stress and serum anti-Müllerian hormone in both infertile (r = 0.041, p = 0.719) and fertile (r = − 0.090, p = 0.353) women. There was also no correlation between psychological distress and serum anti-Müllerian hormone in the infertile (r = − 0.020, p = 0.860) and fertile (r = − 0.049, p = 0.636) groups. Controlling for age and body mass index in multivariate linear regression; stress and psychological distress were not significantly associated with serum anti-Müllerian hormone (B = − 0.005; p = 0.370 and B = − 0.001; p = 0.811).

Conclusion

Self-reported stress and psychological distress are not associated with serum anti-Müllerian hormone levels in infertile and fertile women of reproductive age. Also, ovarian ageing was accelerated in infertile women when compared to fertile women; however, this does not appear to be related to stress or psychological distress. More research is needed to understand factors that may contribute to this accelerated decline.

Expression of genes that regulate follicle development and maturation during ovarian stimulation in poor responders

RESEARCH QUESTION

Sex hormone-binding globulin (SHBG), androgen receptor (AR), LH beta polypeptide (LHB), progesterone receptor membrane component 1 (PGRMC1) and progesterone receptor membrane component 2 (PGRMC2) regulate follicle development and maturation. Their mRNA expression was assessed in peripheral blood mononuclear cells (PBMC) of normal and poor responders, during ovarian stimulation.

DESIGN

Fifty-two normal responders and 15 poor responders according to the Bologna criteria were enrolled for IVF and intracytoplasmic sperm injection and stimulated with 200 IU of follitrophin alpha and gonadotrophin-releasing hormone antagonist. HCG was administered for final oocyte maturation. On days 1, 6 and 10 of stimulation, blood samples were obtained, serum hormone levels were measured, RNA was extracted from PBMC and real-time polymerase chain reaction was carried out to identify the mRNA levels. Relative mRNA expression of each gene was calculated by the comparative 2^-DDCt method.

RESULTS

Differences between mRNA levels of each gene on the same time point between the two groups were not significant. PGRMC1 and PGRMC2 mRNA levels were downregulated, adjusted for ovarian response and age. Positive correlations between PGRMC1 and AR (standardized beta = 0.890, P < 0.001) from day 1 to 6 and PGRMC1 and LHB (standardized beta = 0.806, P < 0.001) from day 1 to 10 were found in poor responders. PGRMC1 and PGRMC2 were positively correlated on days 6 and 10 in normal responders.

CONCLUSIONS

PGRMC1 and PGRMC2 mRNA are significantly decreased during ovarian stimulation, with some potential differences between normal and poor responders.

Association of exposure to air pollution and green space with ovarian reserve hormones levels

Exposure to air pollution has been associated with adverse health effects while exposure to greenspace has been associated with public health benefits. However, the available evidence on the association of exposure to air pollution with ovarian reserve markers is still scarce, with no study on such an association with greenspace exposure. Therefore, this study aimed to investigate the association of exposure to particulate matter with diameter of less than 1, 2.5 and 10 μm (PM₁, PM_2.5, PM₁₀), traffic indicators (distance from women's residence to major roads and total street length in different buffers around women's residential address) and greenspace indicators (residential surrounding greenspace and distance to green spaces) with serum levels of anti-müllerian hormone (AMH) and follicle stimulating hormone (FSH) as markers of ovarian reserve. This cross-sectional study was based on 67 women residing in Sabzevar, Iran (2018). Basal serum levels of FSH and AMH were measured by the enzyme-linked immunosorbent assays (ELISA). Land use regression models were used to estimate PMs concentrations at residential addresses and the average of normalized difference vegetation index (NDVI) in different buffers was used to characterize residential surrounding greenspace. Multiple linear regression models were developed to estimate the association of AMH and FSH with exposure to air pollution, traffic, and greenspace (one at a time) controlled for relevant covariates. In fully adjusted models, there was an inverse association between exposure to PM₁, PM_2.5 as well as total street length in 100 m buffer around women's residence and AMH level (β = -0.89, 95% confidence interval (CI): -1.43, -0.35, P-value ≤ 0.01, β = -1.11, 95% CI: -1.67, -0.55, P-value ≤ 0.01 and β = -0.76, 95% CI: -1.48, -0.50, P-value = 0.03, respectively). Moreover, increase in distance from home to nearest major road as well as residential surrounding greenspace (100 m buffer) and decrease in residential distance to a green space larger than 5000 m² were associated with increase in serum level of AMH. However, we did not observe any significant association between exposure to air pollution, traffic, and greenspace with FSH level. Overall, our findings supported a beneficial association of exposure to greenspace and detrimental association of exposure to air pollution with ovarian reserve.

Does night work affect age at which menopause occurs?

PURPOSE OF REVIEW

To delineate the current state of evidence on the impact of night shift work on age at natural menopause.

RECENT FINDINGS

The only direct evidence is from a single observational study, which indicates that women who work night shifts are at moderately higher risk for earlier menopause and that this risk is more pronounced among younger women. Underlying biological mechanisms have yet to be sufficiently substantiated. A long-held line of inquiry, most strongly propagated by the observed link between night shift work and female breast cancer, is the 'Light at Night' hypothesis, which suggests melatonin-mediated circadian disruption as a potential regulator of reproductive signaling in women. Supporting evidence is found from observations of changes in endogenous melatonin production among night working women or in response to light exposure, and corresponding changes in endogenous ovarian hormone levels and modulated menstrual patterns, among other indications of altered central ovulation-governing processes. Susceptibility to night shift work may be modified by chronotype.

SUMMARY

This review summarizes the literature related to night work and ovulatory regulation in humans, prioritizing population-based evidence to provide motivation for the study of circadian disruption and night shift work as a regulator of menopausal timing.

Perceived Stress and Fecundability: A Preconception Cohort Study of North American Couples

While some epidemiologic studies support the hypothesis that stress can adversely affect fertility, few prospective studies have assessed the association in couples from the general population. We used data from Pregnancy Study Online, a web-based preconception cohort study of pregnancy planners from the United States and Canada (2013-2018), to examine the association between women's and men's perceived stress levels prior to conception and fecundability. Women (aged 21-45 years) and their male partners (aged ≥21 years) who were attempting conception without fertility treatment were eligible. We measured perceived stress using the 10-item Perceived Stress Scale (PSS). We ascertained pregnancy information using bimonthly follow-up questionnaires of female participants. We followed 4,769 couples until self-reported pregnancy, initiation of fertility treatment, loss to follow-up, or 12 menstrual cycles of attempt time, whichever came first. We used proportional probabilities regression models to estimate fecundability ratios and 95% confidence intervals, adjusting for potential confounders. Higher PSS scores among the women were associated with slight reductions in fecundability (comparing PSS scores of ≥25 vs. <10, fecundability ratio = 0.87, 95% confidence interval: 0.74, 1.02). PSS scores among the men were not substantially associated with fecundability.