Timing clinic visits to phases of the menstrual cycle by using a fertility monitor: the BioCycle Study

Neuroactive steroid hormone trajectories across the menstrual cycle in premenstrual dysphoric disorder (PMDD): the PHASE study

It is presently not known whether endogenous neuroactive steroid hormone trajectories across the menstrual cycle are distinguishable in women with premenstrual dysphoric disorder (PMDD). To improve the rigor in this area of research, we implemented a validated study methodology, involving blood sample collection at 8 key menstrual cycle timepoints, following which the study data is realigned so that all women are compared at the same biological window (i.e., menstrual cycle subphase). Using liquid chromatography-mass spectrometry (LC-MS), we analyzed serum levels of nine steroid hormones previously implicated in the etiology of PMDD, including allopregnanolone. Other than progesterone (p ≤ 0.001), none of the steroid hormones displayed significant changes across menstrual cycle subphases when comparing participants with PMDD to the healthy controls. A thorough investigation of the progesterone trajectory showed that its left shift in the luteal phase (e.g., earlier rise in progesterone) exposes women with PMDD to a higher periovulatory progesterone and a more acute withdrawal in the late luteal subphase. Results of the present study indicate that the largely overlooked brief periovulatory subphase should be thoroughly examined in PMDD and agree with prior conclusions that rapid progesterone withdrawal associates with the development of negative affect.

Heightened sensitivity to the disinhibiting effect of alcohol in women during the late follicular phase of the menstrual cycle

Compared with men, women are disproportionately affected by alcohol, including greater risks of physiological damage, behavioral impairment, and relapse. One likely mechanism underlying the sexual disparity in this vulnerability is the fluctuation of ovarian hormones, particularly estradiol (E2), across phases of the menstrual cycle. Several preclinical and clinical studies have shown that higher E2 levels positively correlate with drinking, suggesting E2 may play a significant role in modulating drinking. Inhibitory control also modulates drinking; when it is reduced or compromised by alcohol, the drinker's ability to stop the self-administration of alcohol could be impaired, leading to a binge episode. The present study aimed to examine the degree to which menstrual cycle phase can influence the disinhibiting effect of alcohol. Twenty-four healthy young adult women participated in a within-subjects placebo-controlled study of the acute disinhibiting effect of 0.60 g/kg alcohol over the course of two test sessions. A cued go/no-go task measured the disinhibiting effects of alcohol and placebo beverages during the early follicular phase of the cycle when E2 levels were low and the late follicular phase (i.e., ovulation) when E2 was elevated. Results showed that the disinhibiting effect of alcohol increased nearly twofold during the late follicular phase when E2 was elevated. These findings highlight the role of alcohol-induced disinhibition as a potential behavioral mechanism by which fluctuations in ovarian hormones as a function of the menstrual cycle contribute to increased risk for excessive alcohol use in women. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Variability in Sleep Duration and Biomarkers of Cardiovascular Disease Across the Menstrual Cycle

Variability in sleep duration and cardiovascular health have been infrequently investigated, particularly among reproductive-age women. We examined these associations across the menstrual cycle among a cohort of 250 healthy premenopausal women, aged 18-44 years. The BioCycle study (New York, 2005-2007) collected cardiovascular biomarkers (serum high- and low-density lipoprotein (HDL, LDL), total cholesterol, triglycerides, and C-reactive protein (CRP)) at key time points along the menstrual cycle (follicular, ovulatory, and luteal phases). Women also recorded sleep duration in daily diaries. From these data, we computed L-moments, robust versions of location, dispersion, skewness, and kurtosis. We fitted linear mixed models with random intercepts and inverse probability weighting to estimate associations between sleep variability and cardiovascular biomarkers, accounting for demographic, lifestyle, health, and reproductive factors. Sleep dispersion (any deviation from mean duration) was associated with lower mean LDL for nonshift workers and non-White women. Skewed sleep duration was associated with higher mean CRP and lower mean total cholesterol. Sleep durations with extreme short and long bouts (kurtosis) were associated with a lower mean HDL, but not mean CRP, LDL, or triglycerides. Sleep duration modified associations between sleep dispersion and LDL, HDL, and total cholesterol. Even in young and healthy women, sleep duration variability could influence cardiovascular health.

Periovulatory Subphase of the Menstrual Cycle Is Marked by a Significant Decrease in Heart Rate Variability

(1) Background: High-frequency heart rate variability (HF-HRV) is an essential ultradian rhythm that reflects the activity of the PNS to decelerate the heart. It is unknown how HF-HRV varies across the menstrual cycle (MC), and whether progesterone mediates this potential variation. (2) Methods: We enrolled 33 women in the study to attend eight clinic visits across the MC, during which we measured their resting HF-HRV and collected samples for the analysis of luteinizing hormone (LH) and progesterone. We realigned the study data according to the serum LH surge to the early follicular, mid-follicular, periovulatory, early luteal, mid-luteal and late luteal subphases. (3) Results: Pairwise comparisons between all the subphases showed significant differences between the early follicular and periovulatory subphases (β = 0.9302; p ≤ 0.001) and between the periovulatory and early luteal subphases (β = -0.6955; p ≤ 0.05). Progesterone was positively associated with HF-HRV in the early follicular subphase but not the periovulatory subphase (p ≤ 0.05). (4) Conclusions: The present study shows a significant drop in HF-HRV in the anticipation of ovulation. Further research in this area is critical given the marked cardiovascular disease mortality in women.

Trajectories of Allopregnanolone and Allopregnanolone to Progesterone Ratio across the Six Subphases of Menstrual Cycle

Background: Allopregnanolone is one of the most studied neuroactive steroids; yet, despite its relevance to neuropsychiatric research, it is not known how it, as well as its ratio to progesterone, varies across all six subphases of the menstrual cycle. Two enzymes—5α-dihydroprogesterone and 5α-reductase—convert progesterone to allopregnanolone, and, based on immunohistochemical studies in rodents, the activity of 5α-reductase is considered the rate-limiting step in the formation of allopregnanolone. It is not clear, however, whether the same phenomenon is observed across to the menstrual cycle, and, if so, at what point this takes place. Methods: Thirty-seven women completed the study during which they attended eight clinic visits across one menstrual cycle. We analyzed their allopregnanolone and progesterone serum concentrations using ultraperformance liquid chromatography–tandem mass spectrometry, and we implemented a validated method to realign the data from the original eight clinic study visits, following which we imputed the missing data. Hence, we characterized allopregnanolone concentrations, and the ratio of allopregnanolone:progesterone at six menstrual cycle subphases: (1) early follicular, (2) mid-follicular, (3) periovulatory, (4) early luteal, (5) mid-luteal, and (6) late luteal. Results: There were significant differences in allopregnanolone levels between (1) early follicular and early luteal, (2) early follicular and mid-luteal, (3) mid-follicular and mid-luteal, (4) periovulatory and mid-luteal, and (5) mid-luteal and late luteal. We detected a sharp drop in allopregnanolone:progesterone ratio in the early luteal subphase. Within the luteal subphase, the ratio was the lowest in the mid-luteal subphase. Conclusions: Allopregnanolone concentrations are the most distinct, relative to the other subphases, in the mid-luteal subphase. The shape of the allopregnanolone trajectory across the cycle is similar to that of progesterone; however, the proportion of the two neuroactive steroid hormones is drastically different due to enzymatic saturation, which takes place at the start of the early luteal subphase, but continuing through, and peaking, in the mid-luteal subphase. Hence, the estimated activity of 5α-reductase decreases, but does not cease, at any point across the menstrual cycle.

Mid-Luteal Progesterone Is Inversely Associated with Premenstrual Food Cravings

It is not clear whether progesterone and estradiol associate with premenstrual food cravings, which significantly contribute to cardiometabolic adverse effects associated with obesity. We sought to investigate this question in the present study based on the prior literature showing a protective effect of progesterone on drug craving and extensive neurobiological overlaps between food and drug cravings. We enrolled 37 non-illicit drug- or medication-using women in the study to provide daily ratings of premenstrual food cravings and other symptoms across two-three menstrual cycles, based on which we classified them as premenstrual dysphoric disorder (PMDD) or control participants. In addition, the participants provided blood samples at eight clinic visits across the menstrual cycle. We aligned their mid-luteal progesterone and estradiol using a validated method which relies upon the peak serum luteinizing hormone and analyzed estradiol and progesterone using ultraperformance liquid chromatography tandem mass spectrometry. Hierarchical modeling, adjusted for BMI, showed a significant inverse effect of progesterone (p = 0.038) but no effect of estradiol on premenstrual food cravings. The association was not unique to PMDD or control participants. Results of research to date in humans and rodents showing that progesterone has dampening effects on the salience of the reinforcer translate to premenstrual food cravings.

Reduced Dehydroepiandrosterone-Sulfate Levels in the Mid-Luteal Subphase of the Menstrual Cycle: Implications to Women's Health Research

The regulation of DHEA-sulfate by steroid sulfotransferase (SULT) and steryl-sulfatase (STS) enzymes is a vital process for the downstream formation of many steroid hormones. DHEA-sulfate is the most abundant steroid hormone in the human body; thus, DHEA-sulfate and its hydrolyzed form, DHEA, continue to be evaluated in numerous studies, given their importance to human health. Yet, a basic question of relevance to the reproductive-age female population-whether the two steroid hormones vary across the menstrual cycle-has not been addressed. We applied a validated, multi-step protocol, involving realignment and imputation of study data to early follicular, mid-late follicular, periovulatory, and early, mid-, and late luteal subphases of the menstrual cycle, and analyzed DHEA-sulfate and DHEA serum concentrations using ultraperformance liquid chromatography tandem mass spectrometry. DHEA-sulfate levels started to decrease in the early luteal, significantly dropped in the mid-luteal, and returned to basal levels by the late luteal subphase. DHEA, however, did not vary across the menstrual cycle. The present study deep-mapped trajectories of DHEA and DHEA-sulfate across the entire menstrual cycle, demonstrating a significant decrease in DHEA-sulfate in the mid-luteal subphase. These findings are relevant to the active area of research examining associations between DHEA-sulfate levels and various disease states.

Stress, Fatigue, and Sexual Spontaneity Among Married Couples in a High-Stress Society: Evidence from Sex Diary Data from Singapore

This paper investigates the associations between stress and fatigue and sexual spontaneity among heterosexual married couples in Singapore, a high-income society with high work performance expectations and long working hours. Data on self-reported menstrual dates, sexual activity within the marriage, and stress and fatigue levels were collected from 657 married women aged 25-34 years through biweekly online diaries over 14 weeks. Using a two-way fixed effects logistic model which controlled for time-invariant individual fixed effects and menstrual cycle fixed effects, the paper tests three hypotheses: (1) sexual activity is significantly lower on weekdays compared to weekends and public holidays, (2) sexual activity is significantly lower during periods when women reported higher stress and fatigue, and (3) stress and fatigue are more predictive of sexual activity during weekdays than during weekends. Frequencies of marital sexual intercourse during the diary keeping period were 3.69 and 2.55 per 30 days among women aged 25-29 and 30-34 years, respectively, much lower than ideal frequencies of 6.40 and 5.23. Consistent with all three hypotheses, there was a strong positive weekend effect and a weak but positive public holiday effect, and strong negative effects of both stress and fatigue, especially during weekdays. There was no evidence of compensatory sex on weekends to make up for hectic workweeks. Increased support for work-life balance can contribute to more spontaneous marital sex lives and may reduce underachievement of ideals for sexual intimacy and childbearing in Singapore.

Low Intake of Vegetable Protein is Associated With Altered Ovulatory Function Among Healthy Women of Reproductive Age

CONTEXT

Diets high in plant-based protein have gained popularity due to increasing health concerns regarding consumption of animal products. Though links between intakes of certain protein-rich foods and reproductive disorders have been suggested, the relationship of overall animal and vegetable proteins with reproductive hormones among reproductive-aged women is unknown.

OBJECTIVE

To evaluate the associations between the intake of dietary protein with reproductive hormones and sporadic anovulation among reproductive-aged women.

DESIGN

A prospective cohort study, 2005-2007.

SETTING

University at Buffalo, western New York, United States.

PARTICIPANTS

A total of 259 premenopausal women (18-44 years) without dietary restrictions.

MAIN OUTCOME MEASURE(S)

Serum reproductive hormones were determined up to 8 times per cycle for 2 cycles. Protein intake was assessed the day prior to hormone assessment at 4 visits/cycle using 24-hour recalls.

RESULTS

Overall, 84% of participants met the recommended dietary allowance for total protein set for reproductive-aged women. Neither total nor animal protein intake were associated with reproductive hormones or anovulation. However, vegetable protein intake in the lowest tertile was associated with lower luteal phase progesterone (-18.0%, 95% confidence interval [CI] -30.2, -3.6), higher follicle-stimulating hormone (3.8%, 95% CI 0.2, 7.6), and a higher risk of anovulation (risk ratio [RR] 2.53, 95% CI 1.21, 5.26), compared with the middle tertile. Nuts and seeds were the only protein-rich foods associated with an elevated risk of anovulation (RR 2.12, 95% CI 1.17, 3.85).

CONCLUSIONS

Findings suggest that among women who meet the recommended dietary allowance for total protein, low intake of vegetable, but not animal, protein may disturb normal ovulatory function.

Associations between blood cadmium and endocrine features related to PCOS-phenotypes in healthy women of reproductive age: a prospective cohort study

BACKGROUND

Cadmium is an endocrine disrupting chemical that affects the hypothalamic-pituitary-gonadal axis. Though evidence suggests its potential role in altering androgen synthesis and metabolic pathways that are characteristic of polycystic ovary syndrome (PCOS), its relation in healthy women of reproductive age is largely unknown. As women with mild sub-clinical features of PCOS who do not meet the diagnostic criteria of PCOS may still experience reduced fecundability, investigating associations between cadmium and PCOS-phenotypes among healthy women may provide unique insight into the reproductive implications for many on the PCOS spectrum. Therefore, the objective of this study was to evaluate associations between cadmium and androgens, anti-Müllerian hormone (AMH), and metabolic markers in women of reproductive age.

METHODS

This was a prospective cohort study of 251 healthy premenopausal women without self-reported PCOS (mean age 27.3 years and BMI 24.1 kg/m²). Cadmium was measured in blood collected at baseline. Reproductive hormones and metabolic markers were measured in fasting serum 8 times per menstrual cycle for 2 cycles. Linear mixed models and Poisson regression with a robust error variance were used to examine associations between cadmium and reproductive hormones and metabolic markers and anovulation, respectively.

RESULTS

Median (interquartile range) blood cadmium concentrations at baseline were 0.30 (0.19-0.43) µg/L. Higher levels of testosterone (2.2 %, 95 % confidence interval [CI] 0.4, 4.1), sex hormone-binding globulin (2.9 %, 95 % CI 0.5, 5.5), and AMH (7.7 %, 95 % CI 1.1, 14.9) were observed per 0.1 µg/L increase in cadmium concentrations. An 18 % higher probability of a mild PCOS-phenotype (95 % CI 1.06, 1.31), defined by a menstrual cycle being in the highest quartile of cycle-averaged testosterone and AMH levels, was also found per 0.1 µg/L increase in cadmium levels. No associations were observed for insulin and glucose. These findings were consistent even after analyses were restricted to non-smokers or further adjusted for dietary factors to account for potential sources of exposure.

CONCLUSIONS

Overall, among healthy reproductive-aged women, cadmium was associated with endocrine features central to PCOS, but not with metabolic markers. These suggest its potential role in the hormonal milieu associated with PCOS even at low levels of exposure.

Vitamin D and Reproductive Hormones Across the Menstrual Cycle

STUDY QUESTION

How do the calciotropic hormones (25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and intact parathyroid hormone (iPTH)) vary across the menstrual cycle and do cyclic patterns of reproductive hormones (estradiol, progesterone, LH, FSH) differ by vitamin D status?

SUMMARY ANSWER

Calciotropic hormones vary minimally across the menstrual cycle; however, women with 25-hydroxyvitamin D below 30 ng/ml have lower mean estradiol across the menstrual cycle.

WHAT IS KNOWN ALREADY

Prior human studies suggest that vitamin D status is associated with fecundability, but the mechanism is unknown. Exogenous estrogens and prolonged changes in endogenous estradiol (pregnancy or menopause) influence concentrations of 25-hydroxyvitamin D. In vitro, treatment with 1,25-dihydroxyvitamin D increases steroidogenesis in ovarian granulosa cells. There are little data about changes in calciotropic hormones across the menstrual cycle or cyclic patterns of reproductive hormones by categories of vitamin D status.

STUDY DESIGN, SIZE, DURATION

A prospective cohort study of 89 self-identified white women aged 18-44, across two menstrual cycles. Participants were a subset of the BioCycle Study, a community-based study conducted at the University of Buffalo, 2005-2007.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible participants had self-reported regular menstrual cycles between 21 and 35 days and were not using hormonal contraception or vitamins. Early morning fasting blood samples were drawn at up to eight study visits per cycle. Visits were timed to capture information in all cycle phases. Serum samples for 89 women (N = 163 menstrual cycles) were analyzed for estradiol, progesterone, LH, FSH and 25-hydroxyvitamin D (25(OH)D). Variability in calciotropic hormones within and across menstrual cycles was assessed using intraclass correlation coefficients and non-linear mixed models. Given the relative stability of the calciotropic hormones across the menstrual cycle, non-linear mixed models were used to examine differences in the cyclic patterns of estradiol, progesterone, LH and FSH by categories of each calciotropic hormone (split at the median). These models were conducted for all ovulatory cycles (N = 142 ovulatory menstrual cycles) and were adjusted for age, BMI (measured in clinic) and self-reported physical activity.

MAIN RESULTS AND THE ROLE OF CHANCE

Median 25(OH)D concentration was 29.5 ng/ml (SD 8.4), and only 6% of women had vitamin D deficiency (<20 ng/ml). The mean concentration of 25(OH)D did not differ between the luteal and follicular phase; however, both 1,25(OH)2D and iPTH showed small fluctuations across the menstrual cycle with the highest 1,25(OH)2D (and lowest iPTH) in the luteal phase. Compared with women who had mean 25(OH)D ≥30 ng/ml, women with lower 25(OH)D had 13.8% lower mean estradiol (95% confidence interval: -22.0, -4.7) and 10.8% lower free estradiol (95% CI: -0.07, -0.004). Additionally, compared to women with iPTH ≤36 pg/ml, women with higher concentrations of iPTH had 12.7% lower mean estradiol (95% CI: -18.7, -6.3) and 7.3% lower progesterone (95% CI: -13.3, -0.9). No differences in the cyclic pattern of any of the reproductive hormones were observed comparing cycles with higher and lower 1,25(OH)2D.

LIMITATIONS, REASONS FOR CAUTION

Women included in this study had self-reported 'regular' menstrual cycles and very few were found to have 25(OH)D deficiency. This limits our ability to examine cycle characteristics, anovulation and the effects of concentrations of the calciotropic hormones found in deficient individuals. Additionally, the results may not be generalizable to women with irregular cycles, other races, or populations with a higher prevalence of vitamin D deficiency.

WIDER IMPLICATIONS OF THE FINDINGS

These findings support current clinical practice that does not time testing for vitamin D deficiency to the menstrual cycle phase. We find that women with lower vitamin D status (lower 25(OH)D or higher iPTH) have lower mean concentrations of estradiol across the menstrual cycle. Although this study cannot identify a mechanism of action, further in vitro work or clinical trials may help elucidate the biologic mechanisms linking calciotropic and reproductive hormones.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Intramural Research Programs of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract numbers: HHSN275200403394C, HHSN275201100002I and Task 1 HHSN27500001) and the National Institute of Environmental Health Sciences. There are no competing interests.

Circulating Vascular Endothelial Growth Factor and Soluble fms-Like Tyrosine Kinase-1 as Biomarkers for Endometrial Remodeling Across the Menstrual Cycle

OBJECTIVE

To characterize variation in circulating vascular endothelial growth factor (VEGF) and its receptor, soluble fms-like tyrosine kinase-1 (sFLT-1), across the menstrual cycle in normal ovulating women in relation to reproductive hormones to identify the utility of VEGF and sFLT-1 as peripheral biomarkers of endometrial remodeling.

METHODS

Ninety-six healthy, regularly menstruating ovulatory women, aged 18-44 years, enrolled in the BioCycle Study, a prospective cohort study at a U.S. academic research center. Vascular endothelial growth factor and sFLT-1 were measured in concurrently collected plasma, serum, and urine up to eight times across a single cycle. Reproductive hormones were measured in serum. Mean concentrations of VEGF and sFLT-1 were compared across phases of the cycle, and correlations between specimen types were calculated. Harmonic models estimated associations between VEGF and sFLT-1 and characteristics of hormonal patterns.

RESULTS

No variation in VEGF or sFLT-1 levels were detected over the menstrual cycle. Median (25th percentile, 75th percentile) concentrations of VEGF during the menstrual cycle were 31.2 pg/mL (24.1, 56.9) in plasma, 194.1 pg/mL (125.4, 350.2) in serum, and 101.7 pg/mL (64.2, 165.8) in urine. Plasma and serum measures were consistently correlated, whereas urinary measures were not. Vascular endothelial growth factor was not consistently associated with reproductive hormone concentrations, although sFLT-1 was associated with higher mean and amplitude of estradiol.

CONCLUSION

Circulating VEGF and sFLT-1 did not vary across the menstrual cycle and therefore are unlikely to be useful peripheral biomarkers of endometrial changes across the menstrual cycle. For studies measuring circulating VEGF for other reasons, plasma may be the preferred medium and timing to menstrual cycle phase need not be considered for reproductive-age women.

Serum antioxidant vitamin concentrations and oxidative stress markers associated with symptoms and severity of premenstrual syndrome: a prospective cohort study

Background

It has been suggested that premenstrual syndrome (PMS) may derive from either elevated oxidative stress or reduced antioxidant vitamin levels in the body; however, these relationships have been minimally studied in a large cohort of healthy women. Our objective was to estimate the association between serum concentrations of antioxidant vitamins (A, C, and E) and markers of oxidative stress (F2-isoprostane) with symptoms and severity of PMS.

Methods

The BioCycle study was a prospective cohort study following 259 healthy premenopausal women aged 18–44 years for up to 2 menstrual cycles. Frequency/severity of 20 PMS symptoms were assessed via questionnaires 4 times/cycle, and antioxidant vitamins and oxidative stress biomarkers were measured up to 8 times/cycle to correspond with specific cycle phases. Generalized linear models were used to estimate associations between mean antioxidant concentrations and oxidative stress biomarkers with PMS symptoms and severity; linear mixed models were used to evaluate associations with symptom severity scores within groups (e.g. depression, cravings, pain).

Results

Higher concentrations of serum antioxidant vitamins were largely not associated with prevalence or severity of PMS symptoms. Though a few associations were observed, only associations between mean γ-tocopherol and decreased odds of swelling of the hands/feet survived adjustment for multiple comparisons (OR 0.33, 95% CI 0.16, 0.65, per ug/dL). However, F2-isoprostanes were associated with prevalence and severity of several symptoms specifically related to depression and cravings (depression score β = 0.07, 95% CI 0.02, 0.12, per 10 ug/dL; cravings score β = 0.16, 95% CI 0.10, 0.22, per 10 ug/dL), as well as with classification of PMS severity (OR 1.07, 95% CI 1.01, 1.14, per 10 pg/dL), with these associations surviving adjustment for false discovery rate.

Conclusions

F2-isoprostanes, but not antioxidant vitamins, were associated with select PMS symptoms, as well as symptom and severity categories. Specific symptom relationships merit further research.

Combining Biomarker Calibration Data to Reduce Measurement Error

Biomarker assay measurement often consists of a two-stage process where laboratory equipment yields a relative measure which is subsequently transformed to the unit of interest using a calibration curve. The calibration curve establishes the relation between the measured relative units and sample biomarker concentrations using stepped samples of known biomarker concentrations. Samples from epidemiologic studies are often measured in multiple batches or plates, each with independent calibration experiments. Collapsing calibration information across batches before statistical analysis has been shown to reduce measurement error and improves estimation. Additionally, collapsing in practice can also create an additional layer of quality control (QC) and optimization in a part of the laboratory measurement process that is often highly automated. Principled recalibration is demonstrated via. a three-step process of identifying batches where recalibration might be beneficial, forming a collapsed calibration curve and recalibrating identified batches, and using QC data to assess the appropriateness of recalibration. Here, we use inhibin B measured in biospecimens from the BioCycle study using 50 enzyme-linked immunosorbent assay (ELISA) batches (3875 samples) to motivate and display the benefits of collapsing calibration experiments, such as detecting and overcoming faulty calibration experiments, and thus improving assay coefficients of variation from reducing unwanted measurement error variability. Differences in the analysis of inhibin B by testosterone quartile are also demonstrated before and after recalibration. These simple and practical procedures are minor adjustments implemented by study personnel without altering laboratory protocols which could have positive estimation and cost-saving implications especially for population-based studies.

Plasma volume variation across the menstrual cycle among healthy women of reproductive age: A prospective cohort study

Increases in reproductive hormones like estrogen, play an important role in the remarkable increases in plasma volume observed in pregnancy. Accurate estimates of plasma volume expansion during pregnancy depend on correctly timing and measuring plasma volume in nonpregnant women. However, to date, there is no consensus on the pattern of plasma volume across the menstrual cycle. We prospectively measured plasma volume in 45 women across a single menstrual cycle. A urine-based fertility monitor was used to time three clinic visits to distinct points in the menstrual cycle: the early follicular phase (~day 2), periovulation (~day 12), and the mid-point of the luteal phase (~day 21)-based on a 28-day cycle length. Healthy women aged 18-41 years with regular menstrual cycles and a healthy body weight were enrolled in the study. At each visit, blood samples were collected before and after injection of 0.25 mg/kg body weight of indocyanine green dye (ICG). Pre- and post-ICG injection plasma samples were used to measure plasma volume. Preinjection samples were used to measure ovarian hormones and plasma osmolality. Mean plasma volume was highest during the early follicular phase (2,276 ± 478 ml); it declined to 2,232 ± 509 ml by the late follicular phase and to 2,228 ± 502 ml by the midluteal phase. This study found that overall variations in plasma volume are small across the menstrual cycle. Therefore, in clinical practice and research, the menstrual cycle phase may not be an important consideration when evaluating plasma volume among women of reproductive age.

Comparison of woman-picked, expert-picked, and computer-picked Peak Day of cervical mucus with blinded urine luteinising hormone surge for concurrent identification of ovulation

BACKGROUND

Previous research has demonstrated that women instructed in fertility awareness methods can identify the Peak Day of cervical mucus discharge for each menstrual cycle, and the Peak Day has high agreement with other indicators of the day of ovulation. However, previous studies enrolled experienced users of fertility awareness methods or were not fully blinded.

OBJECTIVE

To assess the agreement between cervical mucus Peak Day identified by fertile women without prior experience on assessing cervical mucus discharge with the estimated day of ovulation (1 day after urine luteinising hormone surge).

METHODS

This study is a secondary analysis of data from a randomised trial of the Creighton Model FertilityCareTM System (CrM), conducted 2003-2006, for women trying to conceive. Women who had no prior experience tracking cervical mucus recorded vulvar observations daily using a standardised assessment of mucus characteristics for up to seven menstrual cycles. Four approaches were used to identify the Peak Day. The referent day was defined as one day after the first identified day of luteinising hormone (LH) surge in the urine, assessed blindly. The percentage of agreement between the Peak Day and the referent day of ovulation was calculated.

RESULTS

Fifty-seven women with 187 complete cycles were included. A Peak Day was identified in 117 (63%) cycles by women, 185 (99%) cycles by experts, and 187 (100%) by computer algorithm. The woman-picked Peak Day was the same as the referent day in 25% of 117 cycles, within ±1 day in 58% of cycles, ±2 days in 84%, ±3 days in 87%, and ±4 days in 92%. The ±1 day and ± 4 days' agreement was 50% and 90% for the expert-picked and 47% and 87% for the computer-picked Peak Day, respectively.

CONCLUSIONS

Women's daily tracking of cervical mucus is a low-cost alternative for identifying the estimated day of ovulation.

The influences of sleep duration, chronotype, and nightwork on the ovarian cycle

Despite research indicating that sleep disorders influence reproductive health, the effects of sleep on reproductive hormone concentrations are poorly characterized. We prospectively followed 259 regularly menstruating women across one to two menstrual cycles (the BioCycle Study, 2005-2007), measuring fasting serum hormone concentrations up to eight times per cycle. Women provided information about daily sleep in diaries and chronotype and night/shift work on a baseline questionnaire. We evaluated percent differences in mean hormone concentrations, the magnitude of shifts in the timing and amplitude of hormone peaks, and the risk for sporadic anovulation associated with self-reported sleep patterns and night/shift work. We estimated chronotype scores - categorizing women below and above the interquartile range (IQR) as "morning" and "evening" chronotypes, respectively. For every hour increase in daily sleep duration, mean estradiol concentrations increased by 3.9% (95% confidence interval [CI] 2.0, 5.9%) and luteal phase progesterone by 9.4% (CI 4.0, 15.2%). Receiving less than 7 hours of sleep per day was associated with slightly earlier rises in peak levels for several hormones. Women reporting night/shift work (n = 77) had lower testosterone relative to women employed without night/shift work (percent difference: -9.9%, CI -18.4, -0.4%). Women with morning chronotypes (n = 47) had earlier rises in estradiol during their cycles and potentially an earlier rise in luteinizing hormone. Compared to those who had intermediate chronotypes, women with evening chronotypes (n = 42) had a later luteinizing hormone peak of borderline statistical significance. A reduced risk for sporadic anovulation was suggested, but imprecise, for increasing hours of daily sleep leading up to ovulation (risk ratio 0.79, CI 0.59, 1.06), while an imprecise increased risk was observed for women with morning chronotypes (risk ratio 2.50, CI 0.93, 6.77). Sleep-related hormonal changes may not greatly alter ovarian function in healthy women, but have the potential to influence gynecologic health.

Interactive effects of ovarian steroid hormones on alcohol use and binge drinking across the menstrual cycle

Patterns and features of substance use and abuse vary across the menstrual cycle in humans. Yet, little work has systematically examined the within-person relationships between ovarian hormone changes and alcohol use across the menstrual cycle. Our study was the first to examine the roles of within-person levels of estradiol (E2) and progesterone (P4) in relation to daily alcohol use and binge drinking in young women. Participants were 22 naturally cycling women, ages 18-22, recruited through a university subject pool who reported any alcohol use and who completed a screening visit assessing study eligibility, followed by 35 subsequent days of data collection. E2 and P4 were obtained via enzyme immunoassay of saliva samples collected by participants each morning, 30 min after waking. Presence and degree of daily substance use were obtained using an adaptation of the Timeline FollowBack Interview completed daily. Results indicated that elevated E2 in the context of decreased P4 levels were associated with higher risk of drinking and binge drinking. These effects were present only on weekend days. Results are suggestive of a dual risk model in which both ovulatory E2 increases and perimenstrual P4 decreases increase risk for drinking. Differential associations of steroids with drinking across the menstrual cycle may suggest the need for clinical assessment of substance use to take into account hormone dynamics and menstrual cycle phase. (PsycINFO Database Record

Tampon use, environmental chemicals and oxidative stress in the BioCycle study

BACKGROUND

Tampons are used by up to 86% of US women and are a rarely considered potential source of pesticide and metal exposure. Tampons may be of particular concern given the likely higher absorption that occurs in the vagina. Our objective was to examine the potential associations between tampon use and metal concentrations, and biomarkers of inflammation and oxidative stress among healthy women.

METHODS

We used information from a prospective cohort of 259 regularly menstruating women, aged 18-44, followed for two menstrual cycles. Tampon use was assessed using information provided in participant study diaries. Metal concentrations were measured from a blood sample collected at enrollment. Oxidative stress and inflammation biomarker concentrations were determined from blood samples collected at up to 8 clinic visits for each cycle. Linear regression models were used to estimate associations of tampon use with metal exposure, and linear mixed models to estimate associations of tampon use with inflammation and oxidative stress biomarkers at different times during the menstrual cycle.

RESULTS

We observed non-significantly higher mean levels of mercury for tampon users compared to non-tampon users (exp(β) = 1.25, 95% CI = 0.93, 1.68). We found no evidence of an association between tampon use and inflammation biomarkers. We observed consistently higher isoprostane levels, an oxidative stress biomarker, among tampon users compared to non-tampon users (e.g. exp.(β) = 1.05, 95%CI = 0.96, 1.16, for the average isoprostane during the menstruating week); however, these results were not statistically significant.

CONCLUSIONS

While our results are not statistically significant, we observed suggestive associations between tampon use and elevated levels of mercury and oxidative stress biomarkers. Although our finding should be interpreted in light of our limitations, they indicate that tampons may be a source of exposure to metals and chemicals that have been largely ignored, and any related health effects are an important public health concern.

Time-varying cycle average and daily variation in ambient air pollution and fecundability

STUDY QUESTION

Does ambient air pollution affect fecundability?

SUMMARY ANSWER

While cycle-average air pollution exposure was not associated with fecundability, we observed some associations for acute exposure around ovulation and implantation with fecundability.

WHAT IS KNOWN ALREADY

Ambient air pollution exposure has been associated with adverse pregnancy outcomes and decrements in semen quality.

STUDY DESIGN, SIZE, DURATION

The LIFE study (2005-2009), a prospective time-to-pregnancy study, enrolled 501 couples who were followed for up to one year of attempting pregnancy.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Average air pollutant exposure was assessed for the menstrual cycle before and during the proliferative phase of each observed cycle (n = 500 couples; n = 2360 cycles) and daily acute exposure was assessed for sensitive windows of each observed cycle (n = 440 couples; n = 1897 cycles). Discrete-time survival analysis modeled the association between fecundability and an interquartile range increase in each pollutant, adjusting for co-pollutants, site, age, race/ethnicity, parity, body mass index, smoking, income and education.

MAIN RESULTS AND THE ROLE OF CHANCE

Cycle-average air pollutant exposure was not associated with fecundability. In acute models, fecundability was diminished with exposure to ozone the day before ovulation and nitrogen oxides 8 days post ovulation (fecundability odds ratio [FOR] 0.83, 95% confidence interval [CI]: 0.72, 0.96 and FOR 0.84, 95% CI: 0.71, 0.99, respectively). However, particulate matter ≤10 microns 6 days post ovulation was associated with greater fecundability (FOR 1.25, 95% CI: 1.01, 1.54).

LIMITATIONS, REASONS FOR CAUTION

Although our study was unlikely to be biased due to confounding, misclassification of air pollution exposure and the moderate study size may have limited our ability to detect an association between ambient air pollution and fecundability.

WIDER IMPLICATIONS OF THE FINDINGS

While no associations were observed for cycle-average ambient air pollution exposure, consistent with past research in the United States, exposure during critical windows of hormonal variability was associated with prospectively measured couple fecundability, warranting further investigation.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (Longitudinal Investigation of Fertility and the Environment study contract nos. #N01-HD-3-3355, NO1-HD-#-3356, N01-HD-3-3358 and the Air Quality and Reproductive Health Study Contract No. HHSN275200800002I, Task Order No. HHSN27500008). We declare no conflict of interest.

Exposure to bisphenol A, chlorophenols, benzophenones, and parabens in relation to reproductive hormones in healthy women: A chemical mixture approach

BACKGROUND

Little is known about the associations of bisphenol A, chlorophenols, benzophenones, and parabens with reproductive hormone levels in women. Our goal was to evaluate the associations between repeated measures of these chemicals and their mixtures with reproductive hormones in women.

METHODS

Longitudinal urine samples from healthy, premenopausal women (n = 143 with 3-5 urine samples each) were measured for bisphenol A, five chlorophenols (2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol, 2,4,5-trichlorophenol, 2,4,6-trichlorophenol, triclosan), two ultraviolet (UV) filters (benzophenone-1, benzophenone-3), and eight parabens and their metabolites (benzyl, butyl, ethyl, heptyl, methyl, propyl, 4-hydroxybenzoic acid (4-HB), 3,4-dihydroxybenzoic acid (3,4-DHB)) over two menstrual cycles. Estradiol, progesterone, luteinizing hormone (LH), and follicle stimulating hormone (FSH) were measured in blood up to 8 times each menstrual cycle. Linear mixed models were used for both single and multi-chemical exposures estimated using principal component analysis. Four factors were identified including: paraben; paraben metabolites and BPA, phenols, and UV filters. Models were adjusted for creatinine, age, race, and body mass index and weighted with inverse probability of exposure weights to account for time varying confounding.

RESULTS

In single-chemical models, 3,4-DHB was associated with estradiol (0.06 (95% confidence interval (CI): 0.001, 0.12)), 2-4-DCP with increased progesterone 0.14 (0.06, 0.21) and decreased FSH -0.08 (-0.11, -0.04), and 4-HB was associated with increased FSH 0.07 (0.01, 0.13). In multi-chemical models, all factors were associated with increased progesterone (beta coefficient range: 0.15 for UV filter factor to 0.32 for paraben factor). The paraben factor and the paraben metabolite and BPA factor were associated with increased estradiol [0.21 (0.15, 0.28); 0.12 (0.07, 0.18)]. The phenol and UV filter factors were associated with decreased estradiol, FSH, and LH. The UV filter factor showed the strongest inverse association with estradiol -0.16 (-0.22, -0.10), FSH -0.12 (-0.17, -0.07), and LH -0.17 (-0.23, -0.10).

CONCLUSION

Mixtures of phenols were associated with changes in reproductive hormones. Such changes could contribute to adverse health in women but additional research is necessary.

Can apps and calendar methods predict ovulation with accuracy?

OBJECTIVE

The accuracy of prediction of ovulation by cycle apps and published calendar methods was determined by comparing to true probability of ovulation.

METHODS

A total of 949 volunteers collected urine samples for one entire menstrual cycle. Luteinizing hormone was measured to assign surge day, enabling probability of ovulation to be determined across different cycle lengths. Cycle-tracking apps were downloaded. As none provided their methodology, four published calendar-based methods were also examined: standard days, rhythm, alternative rhythm and simple calendar method. The volunteer ovulation data was applied to the app/calendar methods to determine their accuracy.

RESULTS

Mean cycle length was 28 days (range: 23-35); 34% of women believed they had a 28-day cycle, but only 15% did. No LH surge was seen for 99 women. Most likely day of ovulation for a 28-day cycle was day 16 (21%). Accuracy of ovulation prediction was no better than 21% by the apps. The standard days and rhythm methods were most likely to predict ovulation (70% and 89%, respectively) but had very low accuracy.

CONCLUSIONS

Ovulation day varies considerably for any given menstrual cycle length, thus it is not possible for calendar/app methods that use cycle-length information alone to accurately predict the day of ovulation. National Clinical Trial Code: NCT01577147. Registry website: www.clinicaltrials.gov .

Dietary minerals, reproductive hormone levels and sporadic anovulation: associations in healthy women with regular menstrual cycles

Although minerals are linked to several reproductive outcomes, it is unknown whether dietary minerals are associated with ovulatory function. We hypothesised that low intakes of minerals would be associated with an increased risk of anovulation. We investigated associations between dietary mineral intake and both reproductive hormones and anovulation in healthy women in the BioCycle Study, which prospectively followed up 259 regularly menstruating women aged 18-44 years who were not taking mineral supplements for two menstrual cycles. Intakes of ten selected minerals were assessed through 24-h dietary recalls at up to four times per cycle in each participant. Oestradiol, progesterone, luteinising hormone (LH), follicle-stimulating hormone (FSH), sex-hormone-binding globulin and testosterone were measured in serum up to eight times per cycle. We used weighted linear mixed models to evaluate associations between minerals and hormones and generalised linear models for risk of anovulation. Compared with Na intake ≥1500 mg, Na intake <1500 mg was associated with higher levels of FSH (21·3 %; 95 % CI 7·5, 36·9) and LH (36·8 %; 95 % CI 16·5, 60·5) and lower levels of progesterone (-36·9 %; 95 % CI -56·5, -8·5). Na intake <1500 mg (risk ratio (RR) 2·70; 95 % CI 1·00, 7·31) and Mn intake <1·8 mg (RR 2·00; 95 % CI 1·02, 3·94) were associated with an increased risk of anovulation, compared with higher intakes, respectively. Other measured dietary minerals were not associated with ovulatory function. As essential minerals are mostly obtained via diet, our results comparing insufficient levels with sufficient levels highlight the need for future research on dietary nutrients and their associations with ovulatory cycles.

Identification and prediction of the fertile window with a new web-based medical device using a vaginal biosensor for measuring the circadian and circamensual core body temperature

Fertility awareness-based (FAB) methods represent a term that includes all family planning methods that are based on the identification of the fertile window. They are based on the woman's observation of physiological signs of the fertile and infertile phases of the menstrual cycle. The first approach consists basically in symptothermal methods accompanied by cervical mucus measurements and clinical menstrual cycling data recording. The second most often used methods are the urinary measurement of E3G and luteinizing hormone (LH) with a personalized computer system. Hence these systems lack the efficacy of the continuous circadian and circamensual measurement of the core body temperature. Only this approach enables the accurate detection of the ovulation during the fertile window. A new medical device called OvulaRing has been developed to fill this gap. In the present study, the system and its first clinical results are presented. OvulaRing is a medical device used just like a tampon. The device is a vaginal ring of evatane that contains an integrated biosensor. This sensor measures continuously every 5 min the core body temperature throughout the entire cycle. This device allows a circadian and circamensual intravaginal exact measurement. With this system, 288 measurements are created per day. The system can detect retrospectively and predict prospectively the fertile window of the users. One hundred and fifty eight women aged between 18 and 45 years used this medical device in an open non-randomized clinical study for 15 months. A total of 470 cycles could be recorded and were able for analysis. By the same time in a subgroup of patients, hormonal assessments of LH, follicle-stimulating hormone, estradiol and progesterone as well as vaginal ultrasound were performed in parallel between the 9th and the 36th day of the cycle. The validation error due to software errors was 0.89% for the retrospective analysis; that means that the accuracy for the detection of the ovulation was 99.11%. Accuracy of 88.8% for a window of 3 days before ovulation, the day of ovulation and the 3 days after ovulation was achieved for the prospective analysis. In the subgroup of woman with recorded pregnancies, it could be shown that after 3.79 months of use (median) pregnancies were observed. In 67.72% in up to 3 months, in 16.36% between 3 and 6 months of use, in 7.27% between 7 and 9 months, in 5.45% between 10 and 12 months and in 1.82% between 13 and 15 months of use of the system. With this new web-based system, a precise determination of the fertile window even in women with ultralong cycles (>35 days) could be detected independently of their personal live circumstances. Exact determination of the fertile window is herewith possible so that OvulaRing represents an evolution in the FAB method for the cycle diagnosis of women with regular, irregular or anovulatory menstrual cycles.

Reproductive steroids and ADHD symptoms across the menstrual cycle

Although Attention-Deficit/Hyperactivity Disorder shows (ADHD) male predominance, females are significantly impaired and exhibit additional comorbid disorders during adolescence. However, no empirical work has examined the influence of cyclical fluctuating steroids on ADHD symptoms in women. The present study examined estradiol (E2), progesterone (P4), and testosterone (T) associations with ADHD symptoms across the menstrual cycle in regularly-cycling young women (N=32), examining trait impulsivity as a moderator. Women completed a baseline measure of trait impulsivity, provided saliva samples each morning, and completed an ADHD symptom checklist every evening for 35days. Results indicated decreased levels of E2 in the context of increased levels of either P4 or T was associated with higher ADHD symptoms on the following day, particularly for those with high trait impulsivity. Phase analyses suggested both an early follicular and early luteal, or post-ovulatory, increase in ADHD symptoms. Therefore, ADHD symptoms may change across the menstrual cycle in response to endogenous steroid changes.

Efficacy of methods for ovulation estimation and their effect on the statistical detection of ovulation-linked behavioral fluctuations

Contention of the ovulatory shift hypothesis is principally supported by failures to replicate previous findings; e.g., recent meta-analytic work suggests that the effects endorsing the hypothesis may not be robust. Some possible limitations in this and other ovulatory-effects research-that may contribute to such controversy arising-are: (a) use of error-prone methods for assessing target periods of fertility that are thought to be associated with behavioral shifts, and (b) use of between-subjects-as opposed to within-subjects-methods. In the current study we present both simulated and empirical research: (a) comparing the ability of between- and within-subject t-tests to detect cyclical shifts; (b) evaluating the efficacy of correlating estimated fertility overlays with potential behavioral shifts; and (c) testing the accuracy of counting methods for identifying windows of cycle fertility. While this study cannot assess whether the ovulatory shift hypothesis or other ovulatory-based hypotheses are tenable, it demonstrates how low power resulting from typical methods employed in the extant literature may be associated with perceived inconsistencies in findings. We conclude that to fully address this issue greater use of within-subjects methodology is needed.

Folate, homocysteine and the ovarian cycle among healthy regularly menstruating women

STUDY QUESTION

How are concentrations of plasma homocysteine and serum folate associated with reproductive hormones and anovulation in regularly menstruating women?

SUMMARY ANSWER

Higher homocysteine was associated with sporadic anovulation and hormonal changes that may be indicative of impaired ovulatory function, but higher serum folate was associated only with higher luteal phase progesterone.

WHAT IS KNOWN ALREADY

Higher folate levels as well as some variants in genes relevant to one-carbon metabolism, are associated with improved reproductive outcomes and responses to fertility treatment, but only a few small studies have explored the relationship between markers of one-carbon metabolism and menstrual cycle characteristics.

STUDY DESIGN, SIZE, DURATION

The BioCycle Study (2005-2007) is a prospective, longitudinal cohort of 259 regularly menstruating women not using hormonal contraceptives or dietary supplements who were followed for up to two menstrual cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Serum folate and reproductive hormones were measured up to eight times per cycle and plasma homocysteine up to three times. Linear mixed models were used to estimate associations between serum folate or plasma homocysteine and log-transformed reproductive hormone levels while accounting for multiple observations and cycles per woman. Generalized estimating equations were used to examine risk of sporadic anovulation. All models were adjusted for age, race, body mass index, cigarette and alcohol use, and energy and fiber intake.

MAIN RESULTS AND THE ROLE OF CHANCE

Higher plasma homocysteine concentrations were associated with lower total estradiol across the cycle (adjusted percent change per unit increase in homocysteine [aPC] -2.3%, 95% CI: -4.2, -0.03), higher follicle stimulating hormone around the time of expected ovulation (aPC 2.4%, 95% CI: 0.2, 4.7) and lower luteal phase progesterone (aPC -6.5%, 95% CI: -11.1, -1.8). Higher serum folate concentrations were associated with higher luteal phase progesterone (aPC per unit increase in folate 1.0%, 95% CI: 0.4, 1.6). Higher homocysteine concentrations at expected ovulation were associated with a 33% increased risk of sporadic anovulation. We observed no risk associated with decreased folate concentrations, but a higher ratio of folate to homocysteine at ovulation was associated with a 10% decreased risk of anovulation.

LIMITATIONS, REASONS FOR CAUTION

Our results are generalizable to healthy women with adequate serum folate levels. The independent influence of homocysteine should be confirmed in larger cohorts and among women with folate deficiency or increased risks of anovulation.

WIDER IMPLICATIONS OF THE FINDINGS

If these findings are confirmed, it is possible that lowering homocysteine with B-vitamins through diet or supplementation could improve ovulatory function in some women.

Study FUNDING/COMPETING INTEREST(S)

This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (Contract numbers: HHSN275200403394C, HHSN275201100002I and Task one HHSN27500001). None of the authors has any conflicts of interest to disclose.

Variance in Mood Symptoms Across Menstrual Cycles: Implications for Premenstrual Dysphoric Disorder

Premenstrual dysphoric disorder (PMDD) remains a controversial diagnosis: Some authors have argued that it pathologizes normal mood changes, and others have questioned the need for daily mood reports across multiple cycles. In the present study, we examined changes in mood among psychologically healthy young participants with regular menstrual cycles. We collected daily reports of negative mood (depression, nervousness, irritability, and fatigue) across two to six consecutive cycles from 27 participants aged 18-35 years, and we used variance decomposition analyses to examine how much of the variance in these daily reports was due to day, cycle, and individual. The majority of variance (79%-98%) was due to daily fluctuations and did not conform to a standard pattern of premenstrual rise/postmenstrual fall. These findings suggest that PMDD is not simply an exaggeration of mood patterns typical for psychologically healthy people. Individual patterns were relatively stable from cycle to cycle; thus tracking deviations from a patient's own normative mood patterns may have greater clinical utility than deviation from a presumptive norm.

Dairy Food Intake Is Associated with Reproductive Hormones and Sporadic Anovulation among Healthy Premenopausal Women

BACKGROUND

Dairy food intake has been associated with infertility; however, little is known with regard to associations with reproductive hormones or anovulation.

OBJECTIVE

We investigated whether intakes of dairy foods and specific nutrients were associated with reproductive hormone concentrations across the cycle and the risk of sporadic anovulation among healthy women.

METHODS

We prospectively measured serum reproductive hormones ≤8 times/menstrual cycle for 2 cycles from 259 regularly menstruating women (mean age: 27.3 y). Dairy food intake was assessed via 24-h dietary recalls 4 times/cycle. Dairy food intakes were assessed by 1) total and low- and high-fat dairy products; 2) dairy nutrients, including fat, lactose, calcium, and phosphorus; and 3) dairy foods, including milk, cheese, butter, cream, yogurt, and ice cream categories. Weighted linear mixed models were used to evaluate associations between dairy nutrients or food intakes and hormone concentrations. Modified Poisson regression models with robust error variance were used to evaluate anovulation. Models were adjusted for age, body mass index, race, physical activity, Mediterranean diet score, total energy, protein, fiber, caffeine, and other hormones.

RESULTS

Each serving increase in total and low- and high-fat dairy foods and all increases in amounts of all dairy nutrients tested were associated with an ∼5% reduction in serum estradiol concentrations but were not associated with anovulation. Total and high-fat dairy food intakes were positively associated with serum luteinizing hormone concentrations. We observed associations between intakes of >0 servings of yogurt (RR: 2.1; 95% CI: 1.2, 3.7) and cream (RR: 1.8; 95% CI: 1.0, 3.2) and a higher risk of sporadic anovulation compared with no intake.

CONCLUSIONS

Our study showed associations between increasing dairy food and nutrient intakes and decreasing estradiol concentrations as well as between cream and yogurt intakes and the risk of sporadic anovulation. These results highlight the potential role of dairy in reproductive function in healthy women.

Variability and exposure classification of urinary phenol and paraben metabolite concentrations in reproductive-aged women

BACKGROUND

Human exposure to phenols and parabens is widespread. Within-person variability of urinary concentrations in healthy women is not well characterized.

OBJECTIVES

To characterize the variability of urinary phenol and paraben concentrations across two months and evaluate the ability of a single spot urine sample to characterize exposure.

METHODS

143 women provided 509 spot urine samples collected across two months of study (3-5 samples/woman). We measured urinary concentrations of 8 phenols: bisphenol A (BPA), benzophenone-3 (BP-3), benzophenone-1 (BP-1), 2,4-dichlorophenol (2,4-DCP), 2,5-dichlorophenol (2,5-DCP), 2,4,5-trichlorophenol (2,4,5-TCP), 2,4,6-trichlorophenol (2,4,6-TCP), triclosan (TCS); and 8 parabens and their metabolites (benzyl (BzP), butyl (BuP), ethyl (EtP), heptyl (HeP), methyl (MeP), propyl (PrP), 4-hydroxybenzoic acid (4-HB), 3,4-dihydroxybenzoic acid (3,4-DHB)). Biomarker variability was characterized using the intraclass correlation coefficient (ICC) and surrogate category analyses were conducted.

RESULTS

ICCs ranged from very low for BPA (0.04) to moderate for BP-3, BP-1, TCS, BzP, and MeP (0.66, 0.58, 0.55, 0.54, and 0.62, respectively). Surrogate analyses suggested that BP-1, BP-3, TCS, 2,4-DCP, BuP, and PrP may be characterized by a single spot sample (sensitivity range 0.76-0.86) but that additional samples were necessary for BPA, HeP, 4-HB, and 3,4-DHB (sensitivity range 0.47-0.61).

CONCLUSIONS

Urinary phenol and paraben metabolite concentrations were variable across two months in healthy women but the degree of reliability differed by the specific biomarker. A small number of samples may sufficiently characterize typical concentrations for BP-3, BP-1, TCS, BuP, and PrP; but additional biospecimens may be necessary to characterize exposure for other compounds, including BPA.

Changes in PYY and gastric emptying across the phases of the menstrual cycle and the influence of the ovarian hormones

Nutrition-related studies avoid the participation of pre-menopausal women due to the potential effect of the menstrual cycle (MC) on their appetite regulation. It is generally accepted that women increase their energy intake during the luteal phase (LPh) compared to the follicular (FPh), however what happens in the menstrual phase (MPh) and how this might be regulated remains uncertain. Although some research indicates changes in the gastric emptying (GE) velocity, whether PYY is affected by the MC phase, remains unknown. The aim of this study was to assess whether eating the same breakfast in each of the three MC phases would change the GE time, the PYY response and post-prandial satiety such that they might affect subsequent food intake. Furthermore, the aim was to associate any potential differences to the fluctuations in estradiol (E₂) and progesterone (P₄) within a MC. Nine naturally cycling women attended to the laboratory to consume a standardised breakfast on three occasions, each of them representing one of the MC phases. Breath samples to measure GE time, plasma samples to quantify PYY levels and hunger scores were collected for a total of 4 h after which food intake was assessed by an ad-libitum buffet lunch. GE and PYY levels changed significantly across the phases of the MC (p < 0.05). GE was correlated to P₄ and E₂-P₄ ratio (r = -0.5 and 0.4, respectively). To conclude, the appetite regulators PYY and GE time change depending upon the MC phases with GE time associated with the ovarian hormone levels which suggests the necessity of controlling the MC phase in studies looking at the appetite response.

Serum caffeine and paraxanthine concentrations and menstrual cycle function: correlations with beverage intakes and associations with race, reproductive hormones, and anovulation in the BioCycle Study

BACKGROUND

Clinicians often recommend limiting caffeine intake while attempting to conceive; however, few studies have evaluated the associations between caffeine exposure and menstrual cycle function, and we are aware of no previous studies assessing biological dose via well-timed serum measurements.

OBJECTIVES

We assessed the relation between caffeine and its metabolites and reproductive hormones in a healthy premenopausal cohort and evaluated potential effect modification by race.

DESIGN

Participants (n = 259) were followed for ≤2 menstrual cycles and provided fasting blood specimens ≤8 times/cycle. Linear mixed models were used to estimate associations between serum caffeine biomarkers and geometric mean reproductive hormones, whereas Poisson regression was used to assess risk of sporadic anovulation.

RESULTS

The highest compared with the lowest serum caffeine tertile was associated with lower total testosterone [27.9 ng/dL (95% CI: 26.7, 29.0 ng/dL) compared with 29.1 ng/dL (95% CI: 27.9, 30.3 ng/dL), respectively] and free testosterone [0.178 ng/mL (95% CI: 0.171, 0.185 ng/dL) compared with 0.186 ng/mL (95% CI: 0.179, 0.194 ng/dL), respectively] after adjustment for age, race, percentage of body fat, daily vigorous exercise, perceived stress, depression, dietary factors, and alcohol intake. The highest tertiles compared with the lowest tertiles of caffeine and paraxanthine were also associated with reduced risk of anovulation [adjusted RRs (aRRs): 0.39 (95% CI: 0.18, 0.87) and 0.40 (95% CI: 0.18, 0.87), respectively]. Additional adjustment for self-reported coffee intake did not alter the reproductive hormone findings and only slightly attenuated the results for serum caffeine and paraxanthine and anovulation. Although reductions in the concentrations of total testosterone and free testosterone and decreased risk of anovulation were greatest in Asian women, there was no indication of effect modification by race.

CONCLUSION

Caffeine intake, irrespective of the beverage source, may be associated with reduced testosterone and improved menstrual cycle function in healthy premenopausal women.

Patterns and prevalence of medication use across the menstrual cycle among healthy, reproductive aged women

PURPOSE

The purpose of this study is to characterize the patterns of medication intake in healthy, reproductive-age women not using hormonal contraception.

METHODS

Two hundered fifty-nine healthy, premenopausal women (18-44 years of age) enrolled in the BioCycle Study (2005-2007) were followed over two menstrual cycles. Women were excluded if they were currently using oral contraceptives or other chronic medications. Over-the-counter and prescription medication use among participants was evaluated daily throughout the study via a diary assessing type of medication, dosage, units, and frequency. Medications were categorized as allergy, antibiotics, central nervous system (CNS), cold and cough, gastrointestinal, musculoskeletal, and pain medication based on primary active ingredient. Medication use within each category was assessed across standardized 28-day cycles to evaluate differences in use across cycle phases (i.e., early, middle, and late).

RESULTS

Medication use was reported by 73% of participants. The most and least frequently used medications, respectively, were pain (69%) and musculoskeletal medications (1%). Pain, CNS, and antibiotic medication use varied significantly across the cycle, with pain and CNS medication more frequently reported during menses and antibiotics more frequently during the luteal phase. Allergy, cold and cough, gastrointestinal, and musculoskeletal medication use did not vary across the cycle.

CONCLUSIONS

Patterns of medication use among reproductive age women vary across the menstrual cycle for certain types of medications, particularly in pain (e.g., Ibuprofen), antibiotics (e,g, Amoxicillin), and CNS (e.g., Adderall) medications. Future studies involving use of these types of medication in premenopausal women may need to consider the relationship of their use to the menstrual cycle. Copyright © 2016 John Wiley & Sons, Ltd.

Dietary fat intake and reproductive hormone concentrations and ovulation in regularly menstruating women

BACKGROUND

Emerging evidence suggests potential links between some dietary fatty acids and improved fertility, because specific fatty acids may affect prostaglandin synthesis and steroidogenesis.

OBJECTIVE

The objective of this exploratory study was to evaluate associations between total and specific types of dietary fat intake and 1) hormone concentrations and 2) the risk of sporadic anovulation in a cohort of 259 regularly menstruating women in the BioCycle Study.

DESIGN

Endogenous reproductive hormones were measured up to 8 times/cycle for up to 2 cycles, with visits scheduled with the use of fertility monitors. Dietary intake was assessed with up to four 24-h recalls/cycle. Linear mixed models and generalized linear models were used to evaluate the associations between dietary fatty acids and both reproductive hormone concentrations and ovulatory status. All models were adjusted for total energy intake, age, body mass index, and race.

RESULTS

Relative to the lowest levels of percentage of energy from total fat, the highest tertile was associated with increased total and free testosterone concentrations (total: percentage change of 4.0%; 95% CI: 0.7%, 7.3%; free: percentage change of 4.1%; 95% CI: 0.5%, 7.7%). In particular, the percentage of energy from polyunsaturated fatty acids (PUFAs) in the highest tertile was associated with increases in total and free testosterone (total: percentage change of 3.7%; 95% CI: 0.6%, 6.8%; free: percentage change of 4.0%; 95% CI: 0.5%, 7.5%). The PUFA docosapentaenoic acid (22:5n-3) was not significantly associated with testosterone concentrations (P-trend = 0.86 in energy substitution models) but was associated with increased progesterone and a reduced risk of anovulation (highest tertile compared with the lowest tertile: RR: 0.42; 95% CI: 0.18, 0.95). Fat intakes were not associated with other reproductive hormone concentrations.

CONCLUSIONS

These results indicate that total fat intake, and PUFA intake in particular, is associated with very small increases in testosterone concentrations in healthy women and that increased docosapentaenoic acid was associated with a lower risk of anovulation.

Serum Antioxidants Are Associated with Serum Reproductive Hormones and Ovulation among Healthy Women

BACKGROUND

Evidence is growing that the equilibrium between reactive oxygen species and antioxidants plays a vital role in women's reproductive health.

OBJECTIVE

The objective of this study was to evaluate variations in serum antioxidant concentrations across the menstrual cycle and associations between antioxidants and reproductive hormones and anovulation among healthy women.

METHODS

The BioCycle Study, a prospective cohort, followed 259 women aged 18-44 y for up to 2 menstrual cycles. Serum fat-soluble vitamin and micronutrient (α-tocopherol, γ-tocopherol, retinol, lutein, lycopene, and β-carotene), ascorbic acid, and reproductive hormone concentrations were measured 5-8 times/cycle. We used weighted linear mixed models to assess associations between antioxidants and hormone concentrations, after adjustment for age, race, body mass index, parity, sleep, pain medication use, total energy intake, concurrent hormones, serum cholesterol, F2-isoprostanes, and other antioxidants. Generalized linear models were used to identify associations with anovulation.

RESULTS

Serum antioxidant concentrations varied across the menstrual cycle. Retinol and α-tocopherol were associated with higher estradiol [RR: 1.00 pg/mL (95% CI: 0.67, 1.34 pg/mL); RR: 0.02 pg/mL (95% CI: 0.003, 0.03 pg/mL), respectively] and testosterone [RR: 0.61 ng/dL (95% CI: 0.44, 0.78 ng/dL); RR: 0.01 ng/dL (95% CI: 0.001, 0.01 ng/dL), respectively]. Ascorbic acid was associated with higher progesterone (RR: 0.15 ng/mL; 95% CI: 0.05, 0.25 ng/mL) and with lower follicle-stimulating hormone (RR: -0.06 mIU/mL; 95% CI: -0.09, -0.03 mIU/mL). The ratio of α- to γ-tocopherol was associated with an increased risk of anovulation (RR: 1.03; 95% CI: 1.01, 1.06).

CONCLUSIONS

These findings shed new light on the intricate associations between serum antioxidants and endogenous hormones in healthy premenopausal women and support the hypothesis that concentrations of serum vitamins affect steroidogenesis even after adjustment for oxidative stress.

Fluctuations of Hyperglycemia and Insulin Sensitivity Are Linked to Menstrual Cycle Phases in Women With T1D

BACKGROUND

Factors influencing glycemic variability in type 1 diabetes (T1D) may play a significant role in the refinement of closed loop insulin administration. Phase of menstrual cycle is one such factor that has been inadequately investigated. We propose that unique individual patterns can be constructed and used as parameters of closed loop systems.

METHOD

Women with T1D on continuous subcutaneous insulin infusion and continuous glucose monitoring were studied for 3 consecutive menstrual cycles. Ovulation prediction kits and labs were used to confirm phase of menstrual cycle. Glycemic risks were assessed using the low- and high blood glucose indices (LBGI and HBGI). Insulin sensitivity (SI) was estimated using a Kalman filtering method from meal and insulin data. Overall change significance for glycemic risks was assessed by repeated measures ANOVA, with specific phases emphasized using contrasts.

RESULTS

Ovulation was confirmed in 33/36 cycles studied in 12 subjects (age = 33.1 ± 7.0 years, BMI = 25.7 ± 2.9 kg/m(2), A1c = 6.8 ± 0.7%). Risk for hyperglycemia changed significantly during the cycle (P = .023), with HBGI increasing until early luteal phase and returning to initial levels thereafter. LBGI was steady in the follicular phase, decreasing thereafter but not significantly. SI was depressed during the luteal phase when compared to the early follicular phase (P ≤ .05). Total daily insulin, carbohydrates, or calories did not show any significant fluctuations.

CONCLUSIONS

Women with T1D have glycemic variability changes that are specific to the individual and are linked to phase of cycle. An increased risk of hyperglycemia was observed during periovulation and early luteal phases compared to the early follicular phase; these changes appear to be associated with decreased insulin sensitivity during the luteal phase.

Alcohol intake, reproductive hormones, and menstrual cycle function: a prospective cohort study

BACKGROUND

Although habitual low-to-moderate alcohol intake has been linked with reduced all-cause mortality and morbidity, the effect of recent alcohol intake on female reproductive function has not been clearly established.

OBJECTIVE

We assessed the relation between acute alcohol consumption, reproductive hormones, and markers of menstrual cycle dysfunction including sporadic anovulation, irregular cycle length, luteal phase deficiency, long menses, and heavy blood loss.

DESIGN

A total of 259 healthy, premenopausal women from Western New York were followed for ≤2 menstrual cycles (2005-2007) and provided fasting blood specimens during ≤8 visits/cycle and four 24-h dietary recalls/cycle. Linear mixed models were used to estimate associations between previous day's alcohol intake and hormone concentrations, whereas Poisson regression was used to assess RR of cycle-average alcohol intake and menstrual cycle function.

RESULTS

For every alcoholic drink consumed, the geometric mean total and free estradiol, total and free testosterone, and luteinizing hormone were higher by 5.26% (95% CI: 1.27%, 9.41%), 5.82% (95% CI: 1.81%, 9.99%), 1.56% (95% CI: 0.23%, 2.90%), 1.42% (95% CI: 0.02%, 2.84%), and 6.18% (95% CI: 2.02%, 10.52%), respectively, after adjustment for age, race, percentage of body fat, perceived stress, pain-medication use, sexual activity, caffeine, and sleep. Binge compared with nonbinge drinking (defined as reporting ≥4 compared with <4 drinks/d, respectively) was associated with 64.35% (95% CI: 18.09%, 128.71%) and 63.53% (95% CI: 17.41%, 127.73%) higher total and free estradiol. No statistically significant associations were shown between cycle-average alcohol intake and menstrual cycle function.

CONCLUSION

Although recent moderate alcohol intake does not appear to have adverse short-term effects on menstrual cycle function, including sporadic anovulation, potential protective and deleterious long-term effects of alterations in reproductive hormones on other chronic diseases warrant additional investigation.

Depressive symptoms and their relationship with endogenous reproductive hormones and sporadic anovulation in premenopausal women

PURPOSE

To determine whether depressive symptoms are associated with ovulation or reproductive hormone concentrations in eumenorrheic women without a reported diagnosis of clinical depression.

METHODS

A prospective cohort of 248 regularly menstruating women, aged 18 to 44 years (27.3 ± 8.2) were evaluated for depressive symptoms at baseline using the 20-item Center for Epidemiological Studies Depression (CES-D) scale and categorized dichotomously (<16, no depressive symptoms [92%] vs. ≥ 16, depressive symptoms [8%]). Serum concentrations of estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were measured up to eight times per cycle for up to two menstrual cycles. Linear mixed models estimated associations between depressive symptoms and hormone concentrations, whereas generalized linear mixed models assessed their relationship with sporadic anovulation.

RESULTS

No significant associations were identified between depressive symptoms and reproductive hormone levels (all P > .05) or the odds of sporadic anovulation (adjusted odds ratio, 1.1; 95% confidence interval, [0.02-5.0]), after adjusting for age, race, body mass index, perceived stress level, and alcohol consumption.

CONCLUSIONS

Despite reported associations between mental health and menstrual cycle dysfunction, depressive symptoms were not associated with reproductive hormone concentrations or sporadic anovulation in this cohort of regularly menstruating women with no recent (within 1 year) self-reported history of clinical depression.

Dietary Carbohydrate Intake Does Not Impact Insulin Resistance or Androgens in Healthy, Eumenorrheic Women

CONTEXT

Diet is proposed to contribute to androgen-related reproductive dysfunction.

OBJECTIVE

This study evaluated the association between dietary macronutrient intake, carbohydrate fraction intake, and overall diet quality on androgens and related hormones, including anti-Müllerian hormone (AMH) and insulin, in healthy, regularly menstruating women.

DESIGN

This was a prospective cohort study from 2005 and 2007.

SETTING

The study was conducted at the University at Buffalo, western New York State, USA.

PARTICIPANTS

Participants were 259 eumenorrheic women without a self-reported history of infertility, polycystic ovary syndrome (PCOS), or other endocrine disorder.

MAIN OUTCOME MEASURES

A 24-hour dietary recall was administered 4 times per menstrual cycle, and hormones were measured 5 to 8 times per cycle for 1 (n = 9) or 2 (n = 250) cycles per woman (n = 509 cycles). Associations between the dietary intake of carbohydrates (starch, sugar, sucrose, and fiber), macronutrients, overall diet quality and hormones (insulin, AMH, and total and free testosterone), as well as the relationship of dietary intake with occurrences of high total testosterone combined with high AMH (fourth quartile of each), ie, the "PCOS-like phenotype," were assessed.

RESULTS

No significant relationships were identified between dietary intake of carbohydrates, percent calories from any macronutrient or overall diet quality (ie, Mediterranean diet score) and relevant hormones (insulin, AMH, and total and free testosterone). Likewise, no significant relationships were identified between dietary factors and the occurrence of a subclinical PCOS-like phenotype.

CONCLUSIONS

Despite evidence of a subclinical continuum of a PCOS-related phenotype of elevated androgens and AMH related to sporadic anovulation identified in previous studies, dietary carbohydrate and diet quality do not appear to relate to these subclinical endocrine characteristics in women without overt PCOS.

Dietary factors and luteal phase deficiency in healthy eumenorrheic women

STUDY QUESTION

Are prospectively assessed dietary factors, including overall diet quality, macronutrients and micronutrients, associated with luteal phase deficiency (LPD) in healthy reproductive aged women with regular menstrual cycles?

SUMMARY ANSWER

Mediterranean Diet Score (MDS), fiber and isoflavone intake were positively associated with LPD while selenium was negatively associated with LPD after adjusting for age, percentage body fat and total energy intake.

WHAT IS KNOWN ALREADY

LPD may increase the risk of infertility and early miscarriage. Prior research has shown positive associations between LPD and low energy availability, either through high dietary restraint alone or in conjunction with high energy expenditure via exercise, but few studies with adequate sample sizes have been conducted investigating dietary factors and LPD among healthy, eumenorrheic women.

STUDY DESIGN, SIZE, DURATION

The BioCycle Study (2005-2007) prospectively enrolled 259 women from Western New York state, USA, and followed them for one (n = 9) or two (n = 250) menstrual cycles.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 18-44 years, with self-reported BMI between 18 and 35 kg/m(2) and cycle lengths between 21 and 35 days, were included in the study. Participants completed baseline questionnaires, four 24-h dietary recalls per cycle and daily diaries capturing vigorous exercise, perceived stress and sleep; they also provided up to eight fasting serum samples during clinic visits timed to specific phases of the menstrual cycle using a fertility monitor. Cycles were included for this analysis if the peak serum luteal progesterone was >1 ng/ml and a urine or serum LH surge was detected. Associations between prospectively assessed diet quality, macronutrients and micronutrients and LPD (defined as luteal duration <10 days) were evaluated using generalized linear models adjusting for age, percentage body fat and total energy intake.

MAIN RESULTS AND THE ROLE OF CHANCE

LPD occurred in 41 (8.9%) of the 463 cycles from 246 women in the final analysis. After adjusting for age, percentage body fat and total energy intake, LPD was positively associated with MDS, adjusted odds ratio (aOR): 1.70 (95% confidence interval [CI]: 1.17, 2.48), P = 0.01. In separate macro- and micronutrient adjusted models, increased fiber and isoflavone intake showed modest positive associations with LPD: fiber (per g), aOR: 1.10 (95% CI: 0.99, 1.23), P = 0.07; and isoflavones (per 10 mg), aOR: 1.38 (95% CI: 0.99, 1.92), P = 0.06. In contrast, selenium (per 10 mcg) was inversely associated with LPD, aOR: 0.80 (95% CI: 0.65, 0.97), P = 0.03. Additional adjustments for relevant lifestyle factors including vigorous exercise, perceived stress and sleep did not appreciably alter estimates.

LIMITATIONS, REASONS FOR CAUTION

The number of LPD cycles was limited, and thus these findings are exploratory. We relied on participant self-report of their medical history to apply exclusion criteria; it is possible that we admitted to the study women with a gynecologic or medical disease who were unaware of their diagnosis.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that diet quality may be associated with LPD among healthy eumenorrheic women. As LPD may contribute to infertility and early miscarriage, further research is warranted to elucidate how dietary factors, such as MDS, may influence LPD. The inverse association we found with selenium is supported by previous research and deserves further investigation to determine whether this finding has pathophysiologic and therapeutic implications.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Intramural Research Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health. No competing interests declared.

Changes in macronutrient, micronutrient, and food group intakes throughout the menstrual cycle in healthy, premenopausal women

PURPOSE

It is thought that total energy intake in women is increased during the luteal versus follicular phase of the menstrual cycle; however, less is understood regarding changes in diet composition (i.e., macro- and micronutrient intakes) across the cycle. The aim of this study was to investigate changes in macronutrient, micronutrient, and food group intakes across phases of the menstrual cycle among healthy women, and to assess whether these patterns differ by ovulatory status.

METHODS

The BioCycle study (2005-2007) was a prospective cohort study of 259 healthy regularly menstruating women age 18-44 who were followed for up to two menstrual cycles. Dietary intake was measured using 24-h dietary recalls, and food cravings were assessed via questionnaire, up to four times per cycle, corresponding to menses, mid-follicular, expected ovulation, and luteal phases. Linear mixed models adjusting for total energy intake were used to evaluate changes across the cycle.

RESULTS

Total protein (P = 0.03), animal protein (P = 0.05), and percent of caloric intake from protein (P = 0.02) were highest during the mid-luteal phase compared to the peri-ovulatory phase. There were also significant increases in appetite, craving for chocolate, craving for sweets in general, craving for salty flavor, and total craving score during the late luteal phase compared to the menstrual, follicular, and ovulatory phases (P < 0.001).

CONCLUSIONS

Our findings suggest an increased intake of protein, and specifically animal protein, as well as an increase in reported food cravings, during the luteal phase of the menstrual cycle independent of ovulatory status. These results highlight a plausible link between macronutrient intake and menstrual cycle phase.

Effects of over-the-counter analgesic use on reproductive hormones and ovulation in healthy, premenopausal women

STUDY QUESTION

Does use of commonly used over-the-counter (OTC) pain medication affect reproductive hormones and ovulatory function in premenopausal women?

SUMMARY ANSWER

Few associations were found between analgesic medication use and reproductive hormones, but use during the follicular phase was associated with decreased odds of sporadic anovulation after adjusting for potential confounders.

WHAT IS KNOWN ALREADY

Analgesic medications are the most commonly used OTC drugs among women, but their potential effects on reproductive function are unclear.

STUDY DESIGN, SIZE, DURATION

The BioCycle Study was a prospective, observational cohort study (2005-2007) which followed 259 women for one (n = 9) or two (n = 250) menstrual cycles.

PARTICIPANTS, SETTING, METHODS

Two hundred and fifty-nine healthy, premenopausal women not using hormonal contraception and living in western New York state. Study visits took place at the University at Buffalo.

MAIN RESULTS AND THE ROLE OF CHANCE

During study participation, 68% (n = 175) of women indicated OTC analgesic use. Among users, 45% used ibuprofen, 33% acetaminophen, 10% aspirin and 10% naproxen. Analgesic use during the follicular phase was associated with decreased odds of sporadic anovulation after adjusting for age, race, body mass index, perceived stress level and alcohol consumption (OR 0.36 [0.17, 0.75]). Results remained unchanged after controlling for potential confounding by indication by adjusting for 'healthy' cycle indicators such as amount of blood loss and menstrual pain during the preceding menstruation. Moreover, luteal progesterone was higher (% difference = 14.0, -1.6-32.1, P = 0.08 adjusted) in cycles with follicular phase analgesic use, but no associations were observed with estradiol, LH or FSH.

LIMITATIONS, REASONS FOR CAUTION

Self-report daily diaries are not validated measures of medication usage, which could lead to some classification error of medication use. We were also limited in our evaluation of aspirin and naproxen which were used by few women.

WIDER IMPLICATIONS OF THE FINDINGS

The observed associations between follicular phase analgesic use and higher progesterone and a lower probability of sporadic anovulation indicate that OTC pain medication use is likely not harmful to reproduction function, and certain medications possibly improve ovulatory function.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (contract # HHSN275200403394C). The authors have no conflicts of interest to disclose.

Comparison between the different methods developed for determining the onset of the LH surge in urine during the human menstrual cycle

PURPOSE

To determine whether an optimal method exists for the detection of the luteinising hormone (LH) surge onset in research datasets of urinary hormonal profiles of menstrual cycles.

METHODS

The scientific literature was searched to compare published methodologies for detection of the LH surge onset in urine. Their performance was tested using complete hormonal profiles from 254 ovulatory cycles from 227 women attempting pregnancy (normal regular menstrual cycles; no known infertility).

RESULTS

Three major methodologies to determine the onset of the LH surge in urine were identified. The key difference between these methods is how the cycle days that contribute to LH baseline assessment are determined: using fixed days (method #1), based on peak LH day (method #2), based on a provisional estimate of the LH surge (method #3). Method #1 requires no prior cycle information, whereas methods #2 and #3 need to consider complete cycle data. The most reliable method for calculation of baseline LH was using 2 days before the estimated surge day, plus the previous 4/5 days.

CONCLUSIONS

Different methods for identification of the urinary LH surge can provide very different determinations of LH surge day, thus care must be taken when comparing between studies that apply different methodologies. The optimal method for determining the onset of the LH surge in urine requires retrospective estimation of day of LH surge to identify the most appropriate part of the cycle to consider as the baseline. This method can be adopted for application in population studies.

The relationship between sugar-sweetened beverages and liver enzymes among healthy premenopausal women: a prospective cohort study

PURPOSE

To prospectively assess the association between sugar-sweetened beverages (SSB), added sugar, and total fructose and serum concentrations of liver enzymes among healthy, reproductive-age women.

METHODS

A prospective cohort of 259 premenopausal women (average age 27.3 ± 8.2 years; BMI 24.1 ± kg/m(2)) were followed up for up to two menstrual cycles, providing up to eight fasting blood specimens/cycle and four 24-h dietary recalls/cycle. Women with a history of chronic disease were excluded. Alanine and aspartate aminotransferases (ALT and AST, respectively) were measured in serum samples. Linear mixed models estimated associations between average SSB, added sugar, and total fructose intake and log-transformed liver enzymes adjusting for age, race, body mass index, total energy and alcohol intake, and Mediterranean diet score.

RESULTS

For every 1 cup/day increase in SSB consumption and 10 g/day increase in added sugar and total fructose, log ALT increased by 0.079 U/L (95 % CI 0.022, 0.137), 0.012 U/L (95 % CI 0.002, 0.022), and 0.031 (0.012, 0.050), respectively, and log AST increased by 0.029 U/L (-0.011, 0.069), 0.007 U/L (0.000, 0.014), and 0.017 U/L (0.004, 0.030), respectively. Women who consumed ≥1.50 cups/day (12 oz can) SSB versus less had 0.127 U/L (95 % CI 0.001, 0.254) higher ALT [percent change 13.5 % (95 % CI 0.1, 28.9)] and 0.102 (95 % CI 0.015, 0.190) higher AST [percent change 10.8 % (95 % CI 1.5, 20.9)].

CONCLUSIONS

Sugar-sweetened beverages were associated with higher serum ALT and AST concentrations among healthy premenopausal women, indicating that habitual consumption of even moderate SSB may elicit hepatic lipogenesis.

Perceived stress, reproductive hormones, and ovulatory function: a prospective cohort study

BACKGROUND

Stress has been shown to suppress ovulation in experimental models, but its effect on human reproduction at the population level is unclear.

METHODS

Healthy women (n = 259), aged 18-44 years from Western New York, were followed for 2 menstrual cycles (2005-2007). Women completed daily perceived stress assessments, a 4-item Perceived Stress Scale (PSS-4) up to 4 times each cycle, and a 14-item PSS at baseline. Mixed model analyses were used to assess effects of stress on log reproductive hormone concentrations and sporadic anovulation.

RESULTS

High versus low daily stress was associated with lower estradiol (-9.5% [95% confidence interval (CI) = -15.6% to -3.0%]), free estradiol (-10.4% [-16.5% to -3.9%]), and luteinizing hormone (-14.8% [-21.3% to -7.7%]) and higher follicle-stimulating hormone (6.2% [95% CI = 2.0% to 10.5%]) after adjusting for age, race, percent body fat, depression score, and time-varying hormones and vigorous exercise. High versus low daily stress was also associated with lower luteal progesterone (-10.4% [95% CI = -19.7% to -0.10%]) and higher odds of anovulation (adjusted odds ratio = 2.2 [95% CI = 1.0 to 4.7]). For each unit increase in daily stress level, women had a 70% higher odds of an anovulatory episode (odds ratio = 1.7 [1.1 to 2.4]). Similar but attenuated results were found for the association between the PSS-4 and reproductive hormones, while null findings were found for the baseline PSS.

CONCLUSION

Daily perceived stress does appear to interfere with menstrual cycle function among women with no known reproductive disorders, warranting further research to explore potential population-level impacts and causal biologic mechanisms.

Reclaiming fertility awareness methods to inform timed intercourse for HIV serodiscordant couples attempting to conceive

INTRODUCTION

Increased life expectancy of HIV-positive individuals during recent years has drawn attention to their quality of life, which includes fulfillment of fertility desires. In particular, heterosexual HIV serodiscordant couples constitute a special group for whom the balance between desired pregnancy and the risk of viral transmission should be carefully considered and optimized. Although advanced assisted reproductive technologies are available, such treatments are expensive and are often unavailable. Moreover, standard viral load testing and antiretroviral therapy may not be accessible due to structural or individual barriers. To reduce the risk of HIV transmission, a lower cost alternative is timed condomless sex combined with other risk-reduction strategies. However, timed condomless sex requires specific knowledge of how to accurately predict the fertile window in a menstrual cycle. The aim of this study was to summarize inexpensive fertility awareness methods (FAMs) that predict the fertile window and may be useful for counselling HIV-positive couples on lower cost options to conceive.

METHODS

Original English-language research articles were identified by a detailed Medline and Embase search in July 2014. Relevant citations in the included articles were also retrieved.

RESULTS AND DISCUSSION

Calendar method, basal body temperature and cervicovaginal mucus secretions are the most accessible and sensitive FAMs, although poor specificity precludes their independent use in ovulation detection. In contrast, urinary luteinizing hormone testing is highly specific but less sensitive, and more expensive. To maximize the chance of conception per cycle, the likelihood of natural conception needs to be assessed with a basic fertility evaluation of both partners and a combination of FAMs should be offered. Adherence to other risk-reduction strategies should also be advised, and timely referral to reproductive medicine specialists is necessary when sub/infertility is suspected.

CONCLUSIONS

FAMs provide effective, economical and accessible options for HIV serodiscordant couples to conceive while minimizing unnecessary viral exposure. It is important for health care providers to initiate conversations about fertility desires in HIV-positive couples and to educate identified couples on safer conception strategies.

Biological variability in serum anti-Müllerian hormone throughout the menstrual cycle in ovulatory and sporadic anovulatory cycles in eumenorrheic women

STUDY QUESTION

Does serum anti-Müllerian hormone (AMH) vary significantly throughout both ovulatory and sporadic anovulatory menstrual cycles in healthy premenopausal women?

SUMMARY ANSWER

Serum AMH levels vary statistically significantly across the menstrual cycle in both ovulatory and sporadic anovulatory cycles of healthy eumenorrheic women.

WHAT IS KNOWN ALREADY

Studies to date evaluating serum AMH levels throughout the menstrual cycle have conflicting results regarding intra-woman cyclicity. No previous studies have evaluated an association between AMH and sporadic anovulation.

STUDY DESIGN, SIZE, DURATION

We conducted a prospective cohort study of 259 regularly menstruating women recruited between 2005 and 2007.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women aged 18-44 years were followed for one (n = 9) or two (n = 250) menstrual cycles. Anovulatory cycles were defined as any cycle with peak progesterone concentration ≤5 ng/ml and no serum LH peak on the mid or late luteal visits. Serum AMH was measured at up to eight-time points throughout each cycle.

MAIN RESULTS AND THE ROLE OF CHANCE

Geometric mean AMH levels were observed to vary across the menstrual cycle (P < 0.01) with the highest levels observed during the mid-follicular phase at 2.06 ng/ml, decreasing around the time of ovulation to 1.79 ng/ml and increasing thereafter to 1.93 (mid-follicular versus ovulation, P < 0.01; ovulation versus late luteal, P = 0.01; mid-follicular versus late luteal, P = 0.05). Patterns were similar across all age groups and during ovulatory and anovulatory cycles, with higher levels of AMH observed among women with one or more anovulatory cycles (P = 0.03).

LIMITATIONS, REASONS FOR CAUTION

Ovulatory status was not verified by direct visualization. AMH was analyzed using the original Generation II enzymatically amplified two-site immunoassay, which has been shown to be susceptible to assay interference. Thus, absolute levels should be interpreted with caution, however, patterns and associations remain consistent and any potential bias would be non-differential.

WIDER IMPLICATIONS OF THE FINDINGS

This study demonstrates a significant variation in serum AMH levels across the menstrual cycle regardless of ovulatory status. This variability, although statistically significant, is not large enough to warrant a change in current clinical practice to time AMH measurements to cycle day/phase.

STUDY FUNDING/COMPETING INTERESTS

This research was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institutes of Health, Bethesda, MD (Contracts # HHSN275200403394C, HHSN275201100002I Task 1 HHSN27500001). The authors have no conflicts of interest to declare.

Assessment of anovulation in eumenorrheic women: comparison of ovulation detection algorithms

OBJECTIVE

To compare previously used algorithms to identify anovulatory menstrual cycles in women self-reporting regular menses.

DESIGN

Prospective cohort study.

SETTING

Western New York.

PATIENT(S)

Two hundred fifty-nine healthy, regularly menstruating women followed for one (n=9) or two (n=250) menstrual cycles (2005-2007).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Prevalence of sporadic anovulatory cycles identified using 11 previously defined algorithms that use E2, P, and LH concentrations.

RESULT(S)

Algorithms based on serum LH, E2, and P levels detected a prevalence of anovulation across the study period of 5.5%-12.8% (concordant classification for 91.7%-97.4% of cycles). The prevalence of anovulatory cycles varied from 3.4% to 18.6% using algorithms based on urinary LH alone or with the primary E2 metabolite, estrone-3-glucuronide, levels.

CONCLUSION(S)

The prevalence of anovulatory cycles among healthy women varied by algorithm. Mid-cycle LH surge urine-based algorithms used in over-the-counter fertility monitors tended to classify a higher proportion of anovulatory cycles compared with luteal-phase P serum-based algorithms. Our study demonstrates that algorithms based on the LH surge, or in conjunction with estrone-3-glucuronide, potentially estimate a higher percentage of anovulatory episodes. Addition of measurements of postovulatory serum P or urine pregnanediol may aid in detecting ovulation.

Sexual activity, endogenous reproductive hormones and ovulation in premenopausal women

We investigated whether sexual activity was associated with reproductive function in the BioCycle Study, a prospective cohort study that followed 259 regularly menstruating women aged 18 to 44years for one (n=9) or two (n=250) menstrual cycles in 2005-2007. Women were not attempting pregnancy nor using hormonal contraceptives. History of ever having been sexually active was assessed at baseline and frequency of sexual activity, defined as vaginal-penile intercourse, was self-reported daily throughout the study. Serum concentrations of estradiol, luteinizing hormone (LH), follicle-stimulating hormone (FSH), progesterone, and testosterone were measured up to 8times/cycle. Sporadic anovulation was identified using peak progesterone concentration. Linear mixed models were used to estimate associations between sexual activity and reproductive hormone concentrations and generalized linear models were used to estimate associations with sporadic anovulation. Models were adjusted for age, race, body mass index, perceived stress, and alcohol consumption and accounted for repeated measures within women. Elevated concentrations of estrogen (+14.6%, P<.01), luteal progesterone (+41.0%, P<.01) and mid-cycle LH (+23.4%, P<.01), but not FSH (P=.33) or testosterone (P=.37), were observed in sexually active women compared with sexually inactive women (no prior and no study-period sexual activity); sexually active women had lower odds of sporadic anovulation (adjusted odds ratio=0.34, 95% confidence interval: 0.16-0.73). Among sexually active women, frequency of sexual activity was not associated with hormones or sporadic anovulation (all P>.23). Findings from our study suggest that ever having been sexually active is associated with improved reproductive function, even after controlling for factors such as age.