Vaginal bleeding patterns among rural highland Bolivian women: relationship to fecundity and fetal loss

More than blood: app-tracking reveals variability in heavy menstrual bleeding construct

BACKGROUND

Heavy menstrual bleeding (HMB) is associated with impaired quality of life and may signal serious health problems. Unresolved challenges in measuring menstrual bleeding and identifying HMB have hampered research and clinical care. Self-reported bleeding histories are commonly used but these may be influenced by recall bias, personal beliefs regarding "normal" flow volume, and the experience of other physical symptoms or disruptions to daily life. The potential usefulness of menstrual-tracking mobile applications, which allow real-time user-entered data recording, for assessing HMB has not been studied. We evaluated recall bias in reported period duration, the relationship of tracked period duration and daily flow volume to subsequently reported period heaviness, variation in quality of life associated with increasing period heaviness, and the advantages and limitations of using app-tracked data for clinical and research purposes.

METHODS

An online questionnaire was distributed to current users of Clue, a commercially available menstrual health tracking app, asking them to characterize their last period. We compared responses to the user's corresponding Clue app-tracked data. The study sample comprised 6546 U.S.-based users (aged 18-45 years).

RESULTS

Increasing reported heaviness was associated with increasing app-tracked period length and days of heavy flow, impaired quality-of-life (especially body pain severity), and disrupted activities. Of those reporting having had a heavy/very heavy period, ~ 18% had not tracked any heavy flow, but their period length and quality-of-life indicators were similar to those who had tracked heavy flow. Sexual/romantic activities were the most affected across all flow volumes. Compared to app-tracked data, 44% recalled their exact period length; 83% recalled within ± 1 day. Overestimation was more common than underestimation. However, those with longer app-tracked periods were more likely to underestimate period length by ≥ 2 days, a pattern which could contribute to under-diagnosis of HMB.

CONCLUSION

Period heaviness is a complex construct that encapsulates flow volume and, for many, several other bleeding-associated experiences (period length, bodily impairments, disruptions of daily activities). Even very precise flow volume assessments cannot capture the multi-faceted nature of HMB as experienced by the individual. Real-time app-tracking facilitates quick daily recording of several aspects of bleeding-associated experiences. This more reliable and detailed characterization of bleeding patterns and experiences can potentially increase understanding of menstrual bleeding variability and, if needed, help to guide treatment.

Recognizing normal reproductive biology: A comparative analysis of variability in menstrual cycle biomarkers in German and Bolivian women

The idealized "normal" menstrual cycle typically comprises a coordinated ebb and flow of hormones over a 28-day span with ovulation invariably shown at the midpoint. It's a pretty picture-but rare. Systematic studies have debunked the myth that cycles occur regularly about every 28 days. However, assumptions persist regarding the extent and normalcy of variation in other cycle biomarkers. The processes of judging which phenotypic variants are "normal" is context dependent. In everyday life, normal is that which is most commonly seen. In biomedicine normal is often defined as an arbitrarily bounded portion of the phenotype's distribution about its statistical mean. Standards thus defined in one population are problematic when applied to other populations; population specific standards may also be suspect. Rather, recognizing normal female reproductive biology in diverse human populations requires specific knowledge of proximate mechanisms and functional context. Such efforts should be grounded in an empirical assessment of phenotypic variability. We tested hypotheses regarding cycle biomarker variability in women from a wealthy industrialized population (Germany) and a resource-limited rural agropastoral population (Bolivia). Ovulatory cycles in both samples displayed marked but nonetheless comparable variability in all cycle biomarkers and similar means/medians for cycle and phase lengths. Notably, cycle and phase lengths are poor predictors of mid-luteal progesterone concentrations. These patterns suggest that global and local statistical criteria for "normal" cycles would be difficult to define. A more productive approach involves elucidating the causes of natural variation in ovarian cycling and its consequences for reproductive success and women's health.

Field methods and strategies for assessing female reproductive functioning

A detailed understanding of female reproductive functioning is important to many disciplines including anthropology, evolutionary theory, demography, psychology, and biomedicine. In this article, I describe strategies and methods that have been used successfully in community-based studies of human reproduction, many in remote locales, to produce high quality biomarker data. These techniques are applicable to a wide range of research questions and populations, and to persons from adolescence through senescence. I give particular attention to the inherent challenges imposed by the cyclical and somewhat unpredictable nature of the hypothalamic-pituitary-ovarian axis including the necessity and difficulty of ascertaining the timing and occurrence of ovulation, the limits of different sampling regimes for capturing fluctuations in reproductive hormones, and the critical importance of recognizing and, when possible, reducing selection bias. I discuss the relative advantages and disadvantages of collecting saliva, urine, and dried blood spots, and describe some of the subtleties involved in collecting contamination-free samples. Once samples are collected, they must be stored in a manner that minimizes degradation; I describe techniques to keep samples cold even without access to electricity or dry ice. I also discuss various issues that should be considered during initial discussions with a laboratory and when samples are assayed by the laboratory. I include examples of techniques that have worked well in actual field studies, and examples of flawed analytical approaches that should be avoided. With these and other tools, even under technology-sparse conditions, researchers can investigate variability in human physiology across the breadth of human habitats.

Menstrual cycle characteristics and fecundability in a North American preconception cohort

PURPOSE

The aim of this study was to evaluate the association between menstrual cycle characteristics in early life and adulthood and fecundability.

METHODS

Pregnancy Study Online (PRESTO) is an Internet-based preconception cohort study of pregnancy planners from the United States and Canada. During the preconception period, we enrolled 2189 female pregnancy planners aged 21-45 years who had been attempting conception for ≤6 cycles. Women self-reported menstrual cycle characteristics via an online baseline questionnaire, and pregnancy status was ascertained through bimonthly follow-up questionnaires. Proportional probabilities models were used to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs), adjusting for potential confounders.

RESULTS

Compared with usual menstrual cycle lengths of 27-29 days, cycle lengths of <25 (FR = 0.81, 95% CI: 0.54-1.22) and 25-26 days (FR = 0.92, 95% CI: 0.75-1.14) were associated with reduced fecundability. Compared with women who reached menarche at the age of 12-13 years, those who reached menarche at <12 years had reduced fecundability (FR = 0.87, 95% CI: 0.76-0.99). Women whose cycles never regularized after menarche (FR = 0.93, 95% CI: 0.81-1.06) had slightly reduced fecundability compared with women whose cycles regularized within 2 years of menarche. Bleed length and heaviness of bleeding were not appreciably associated with fecundability.

CONCLUSIONS

Menstrual cycle characteristics, specifically cycle length and age at menarche, may act as markers of fertility potential among pregnancy planners.

The relationship between food frequency and menstrual distress in high school females

Background:

Nutrition pattern is one of the important factors predicting menstrual distress, which varies among different cultures and countries. The purpose of this study is to determine the relationship between food frequency and menstrual distress in high school girls from Mashhad.

Materials and Methods:

This cross-sectional study was conducted in 2012 using a two-stage sampling method on 407 high school female students from Mashhad who met the inclusion criteria. Subjects completed questionnaires of demographic characteristics, food frequency, and Menstrual Distress Questionnaire (MDQ) during three phases of the menstrual cycle (a week before bleeding, during menstrual bleeding period, and a week after menstruation). The collected data were analyzed by statistical tests such as Pearson correlation coefficient test, independent Student's t-test, and one-way analysis of variance (ANOVA).

Results:

Results showed that 87.7% of the students were at moderate economic status, 82.2% were exposed to cigarette smoke, 94.8% had mothers without university education, and 9.4% had working mothers. About 71% of the students reported minor pre-menstruation distress, 81% reported minor distress during bleeding, and 39% reported minor post-menstruation distress. In addition, the mean (SD) values for sweet–fatty foods, salty–fatty foods, fast foods, and caffeine were 3.6, 3.3, 1.3, and 10.2 per week, respectively. In addition, Pearson correlation coefficient test showed no significant correlation between total menstruation distress and food frequency (P > 0.05).

Conclusions:

With regard to the inappropriate food frequency and high intensity of menstrual distress among high school students and as health care and educational efforts for prevention and health promotion in society are among the duties of health workers, the results of this study can help the officials involved in education to emphasize on nutrition and the menstrual health of students.

Gene x environment interactions impact endometrial function and the menstrual cycle: PROGINS, life history, anthropometry, and physical activity

OBJECTIVES

We assessed the impact of a high frequency, functionally significant allelic variant of the progesterone receptor gene (PROGINS) on endometrial function and menstrual cycle characteristics. Further we asked whether PROGINS moderates the impact of life history characteristics, anthropometric measures, and physical activity on endometrial function.

METHODS

Fifty-two women were genotyped for the PROGINS variant, provided life history information, and had anthropometric measurements made. Women monitored their menstrual bleeding for three cycles, performed mid-cycle urinary ovulation tests, and recorded physical activity. A subset of women provided daily saliva samples and had mid-luteal endometrial thickness measurements taken during the third menstrual cycle. Salivary progesterone was assayed using ELISAs. The direct impact of PROGINS on endometrial and menstrual cycle characteristics was determined via independent t-tests with Bonferroni correction. Interactions between PROGINS and covariates were assessed by moderated regression.

RESULTS

PROGINS did not directly impact any indicator of endometrial function. However, PROGINS caused an increase in menstrual cycle length with increasing mid-luteal progesterone levels; the opposite relationship was present in noncarriers (P < 0.05). Additionally, PROGINS interacted with four of six anthropometric measures (BMI, waist circumference, height, and waist-hip ratio) to impact endometrial function, however, interactions between PROGINS and life history variables, or physical activity was limited.

CONCLUSIONS

The gene x environment interactions we report suggest that PROGINS alters endometrial sensitivity to maternal energetic condition. Thus, the possibility of genetically-based variation in sensitivity to energetic stress should be considered in future adaptive models of women's reproduction.

Fifty fertile years: anthropologists' studies of reproduction in high altitude natives

Early European colonists of the Andes had difficulties in reproducing, a fact that underpins the hypothesis that reproduction is impaired amongst all humans at high altitudes. Yet a 16th century missionary wrote, "… the Indians are healthiest and where they multiply the most prolifically is in these same cold air-tempers, … [yet most children of the Spaniards] when born in such regions do not survive." These observations suggest that humans at high altitudes are subjected to strong natural selection from hypoxia, cold and limited food sources and, furthermore, that human populations can and have adapted, and continue to adapt, to these conditions. Informed by multiple approaches and theoretical frameworks, anthropologists have investigated to what extent and precisely how high altitude environments impact human reproductive functioning and fertility. Analyses of the proximate determinants of natural fertility suggest that behaviors (breast/infant feeding practices in the Andes, and marriage practices and religious celibacy in the Himalaya) are major determinants of fertility in high altitude populations. Furthermore, data from Project REPA (Reproduction and Ecology in Provincía Aroma), a longitudinal study in rural Bolivia, demonstrate that fecundity is not impaired in this indigenous altiplano population, and that the risk for early pregnancy loss (EPL) is not elevated by environmental hypoxia but does vary seasonally with the agricultural cycle (contra to the assumption that EPLs are due almost entirely to genetically flawed concepti). This review discusses these and other findings that reveal the complex and dynamic adaptations of human reproductive functioning in high altitude environments.

Darwin's legacy: an evolutionary view of women's reproductive and sexual functioning

On the Origin of species, published just over 150 years ago, has deeply influenced thinking in both scientific and wider communities. Darwin's legacy includes recognition of the fact that all organisms evolve; that variation within and between species is natural and normal; and that an evolutionary approach to understanding the sources and consequences of this variation comprises theoretical frameworks, testable hypotheses, and rigorously collected evidence. With an eye toward facilitating communication and productive collaboration among researchers from different intellectual traditions who nonetheless share a common interest in women's reproductive and sexual functioning, we discuss evolutionary concepts and models, summarize the known variability in ovarian functioning and consider the implications of this variability for conducting sex research, and evaluate the relative merits of various biomarkers that serve as proxy measurements of a woman's reproductive and hormonal status. With these perspectives and methods from reproductive ecology at hand, we examine several contentious issues: the links between hormones and sexuality in premenopausal and perimenopausal women, the causes of premenstrual syndrome, and the existence (or not) of menstrual synchrony. In none of these cases is as much known as is often claimed. In each, there are abundant opportunities for innovative, albeit challenging, research.

A prospective cohort study of menstrual characteristics and time to pregnancy

The authors examined the association between menstrual characteristics and time to pregnancy among 2,653 Danish women enrolled in a prospective cohort study (2007-2009). Menstrual characteristics were reported at baseline. Outcome data were updated bimonthly until pregnancy, fertility treatment, loss to follow-up, or end of observation (12 cycles). Adjusted fecundability ratios and 95% confidence intervals were estimated by using discrete-time Cox regression models. Relative to average cycle lengths (27-29 days), fecundability ratios for cycle lengths <25, 25-26, 30-31, 32-33, and ≥34 days were 0.64 (95% confidence interval (CI): 0.49, 0.84), 0.94 (95% CI: 0.77, 1.13), 1.10 (95% CI: 0.97, 1.25), 1.35 (95% CI: 1.06, 1.73), and 1.17 (95% CI: 0.91, 1.49), respectively. Compared with cycles that regularized within 2 years after menarche, fecundability ratios for cycles that regularized 2-3 and ≥4 years after menarche were 0.90 (95% CI: 0.80, 1.02) and 0.89 (95% CI: 0.77, 1.03), respectively. Fecundability ratios were 0.87 (95% CI: 0.72, 1.05) comparing <3 with 3-4 days of menstrual bleeding and 0.70 (95% CI: 0.43, 1.13) comparing very heavy with moderate flow. In the present study, shorter cycle length was associated with delayed time to pregnancy. Age at menarche, time to menstrual regularization, and duration or intensity of menstrual flow were not appreciably associated with fecundability.

Natural selection of human embryos: decidualizing endometrial stromal cells serve as sensors of embryo quality upon implantation

Background

Pregnancy is widely viewed as dependent upon an intimate dialogue, mediated by locally secreted factors between a developmentally competent embryo and a receptive endometrium. Reproductive success in humans is however limited, largely because of the high prevalence of chromosomally abnormal preimplantation embryos. Moreover, the transient period of endometrial receptivity in humans uniquely coincides with differentiation of endometrial stromal cells (ESCs) into highly specialized decidual cells, which in the absence of pregnancy invariably triggers menstruation. The role of cyclic decidualization of the endometrium in the implantation process and the nature of the decidual cytokines and growth factors that mediate the crosstalk with the embryo are unknown.

Methodology/Principal Findings

We employed a human co-culture model, consisting of decidualizing ESCs and single hatched blastocysts, to identify the soluble factors involved in implantation. Over the 3-day co-culture period, approximately 75% of embryos arrested whereas the remainder showed normal development. The levels of 14 implantation factors secreted by the stromal cells were determined by multiplex immunoassay. Surprisingly, the presence of a developing embryo had no significant effect on decidual secretions, apart from a modest reduction in IL-5 levels. In contrast, arresting embryos triggered a strong response, characterized by selective inhibition of IL-1β, -6, -10, -17, -18, eotaxin, and HB-EGF secretion. Co-cultures were repeated with undifferentiated ESCs but none of the secreted cytokines were affected by the presence of a developing or arresting embryo.

Conclusions

Human ESCs become biosensors of embryo quality upon differentiation into decidual cells. In view of the high incidence of gross chromosomal errors in human preimplantation embryos, cyclic decidualization followed by menstrual shedding may represent a mechanism of natural embryo selection that limits maternal investment in developmentally impaired pregnancies.

Bleeding following pregnancy loss before 6 weeks' gestation

BACKGROUND

Pregnancy loss before 6 weeks' gestation is common, but little has been reported about the associated bleeding. We compared women's bleeding following a pregnancy loss before 6 weeks' gestation with their typical menstruation.

METHODS

Women provided daily urine samples while trying to become pregnant and recorded the number of pads and tampons used each day. Thirty-six women had complete bleed data for a loss before 6 weeks' gestation and one or more non-pregnant cycles.

RESULTS

Mean bleed length following a pregnancy loss was 0.4 days longer than the woman's average menstrual bleed (P = 0.01), primarily because of more days of light bleeding. Although there was no overall increase in the total number of pads plus tampons used, women with losses bled less than their typical menses following pregnancies of very short duration and more than usual for the pregnancies lasting the longest.

CONCLUSIONS

Overall, the bleeding associated with pregnancy loss before 6 weeks' gestation is similar to menstrual bleeding and unlikely to be recognized as pregnancy loss. The intriguing finding that pregnancies of very short duration were associated with less bleeding than the woman's typical menses might reflect endometrial factors associated with loss.

Menstrual cycle characteristics: associations with fertility and spontaneous abortion

BACKGROUND

Epidemiologists often use menstrual cycle patterns as indicators of endocrine function in environmental and occupational studies, yet few studies have considered whether menstrual cycle characteristics are associated with fertility or pregnancy outcome.

METHODS

We prospectively studied 470 women to determine whether cycle length or bleed length were associated with fertility or spontaneous abortion. Women completed daily diaries with information on menstrual bleeding, intercourse, birth control use, and covariates. For each menstrual cycle, women collected at least 2 urine samples, which were assayed for human chorionic gonadotropin to define early pregnancies. Women were followed for 1 year or until the end of a clinical pregnancy.

RESULTS

Cycles with lengths of 30 to 31 days preceded cycles with the highest fecundity. Shorter cycles were less likely to be followed by conception (fecundity ratio [FR] = 0.6; 95% confidence interval [CI] = 0.4-1.0). Compared with 30- to 31-day cycles, conceptions after shorter and longer cycles were more likely to be spontaneously aborted (for shorter cycles, odds ratio [OR] = 3.0 [95% CI = 0.9-9.6] and for longer cycles, OR = 3.0 [0.9-10.6]). Cycles with 5 days of menstrual bleeding had the highest fecundity. Cycles with up to 4 days of bleeding had lower fecundity (for bleed lengths of 4 days, FR = 0.5 [0.3-0.8] and for bleed lengths less than 4 days, FR = 0.6 [0.3-0.9]). Spontaneous abortion was less likely after bleeds greater than 5 days (OR = 0.4 [0.1-1.1]) when compared with 5-day bleeds.

CONCLUSIONS

Menstrual cycle characteristics appear to be associated with fertility and spontaneous abortion.

Epidemiological transitions, reproductive health, and the Flexible Response Model

In concert with improving standards of living since the mid-19th century, chronic and non-infectious diseases replaced infectious diseases as the major causes of mortality in more developed countries. Thus, economic development has been seen as one strategy to improve women's reproductive health. However, rates of two of the major contributors to women's illness, maternal mortality and breast cancer, do not correspond well with the level of economic development. Drawing upon our longitudinal study of reproductive functioning among rural Bolivians (Project Reproduction and Ecology in Provincia Aroma (REPA)), we propose an evolutionary model to explain variation in certain aspects of women's reproductive health. Our findings suggest new avenues of inquiry into the determinants of reproductive health and have implications for improving the well-being of women worldwide.