The use of biochemical assays in epidemiologic studies of reproduction

Constipation and diarrhea during the menopause transition and early postmenopause: observations from the Seattle Midlife Women's Health Study

OBJECTIVE

To assess the relationship of constipation and diarrhea severity during the menopause transition (MT) with age, MT stage, reproductive biomarkers, stress-related biomarkers, and stress-related perceptions.

METHODS

From 1990 to 1992, women aged 35 to 55 years were recruited from the greater Seattle area; 291 of them consented to ongoing (1990-2013) annual data collection by daily menstrual calendar, health diary, and annual health questionnaire. A subset (n = 131) provided a first morning voided urine specimen (1997-2013). These were assayed for levels of E1G, follicle-stimulating hormone, testosterone, cortisol, norepinephrine, and epinephrine. Mixed-effects modeling was used to identify how changes in constipation and diarrhea severity over time related to age, MT stage, reproductive biomarkers, stress-related biomarkers, and stress-related perceptions.

RESULTS

In a univariate model, age, late reproductive (LR) stage, tension, and anxiety were all significantly and positively related to constipation severity, whereas cortisol was significantly and negatively associated. In a multivariate model, only tension and cortisol remained significant predictors of constipation severity (P < 0.05). In a univariate model, age, LR stage, and estrone glucuronide were significantly and negatively associated with diarrhea severity, whereas tension, anxiety, and perceived stress were significantly and positively related. In a multivariate model, only tension and age remained significant predictors of diarrhea severity.

CONCLUSIONS

Key reproductive hormones do not play a significant role in constipation or diarrhea severity in the MT. In contrast, stress perception, tension, anxiety, and cortisol do. These factors should be evaluated in further research involving constipation and diarrhea.

Early embryo mortality in natural human reproduction: What the data say

How many human embryos die between fertilisation and birth under natural conditions? It is widely accepted that natural human embryo mortality is high, particularly during the first weeks after fertilisation, with total prenatal losses of 70% and higher frequently claimed. However, the first external sign of pregnancy occurs two weeks after fertilisation with a missed menstrual period, and establishing the fate of embryos before this is challenging. Calculations are additionally hampered by a lack of data on the efficiency of fertilisation under natural conditions. Four distinct sources are used to justify quantitative claims regarding embryo loss: (i) a hypothesis published by Roberts & Lowe in TheLancet  is widely cited but has no practical quantitative value; (ii) life table analyses give consistent assessments of clinical pregnancy loss, but cannot illuminate losses at earlier stages of development; (iii) studies that measure human chorionic gonadotrophin (hCG) reveal losses in the second week of development and beyond, but not before; and (iv) the classic studies of Hertig and Rock offer the only direct insight into the fate of human embryos from fertilisation under natural conditions. Re-examination of Hertig’s data demonstrates that his estimates for fertilisation rate and early embryo loss are highly imprecise and casts doubt on the validity of his numerical analysis. A recent re-analysis of hCG study data concluded that approximately 40-60% of embryos may be lost between fertilisation and birth, although this will vary substantially between individual women. In conclusion, natural human embryo mortality is lower than often claimed and widely accepted. Estimates for total prenatal mortality of 70% or higher are exaggerated and not supported by the available data.

Early embryo mortality in natural human reproduction: What the data say

How many human embryos die between fertilisation and birth under natural conditions? It is widely accepted that natural human embryo mortality is high, particularly during the first weeks after fertilisation, with total prenatal losses of 70% and higher frequently claimed. However, the first external sign of pregnancy occurs two weeks after fertilisation with a missed menstrual period, and establishing the fate of embryos before this is challenging. Calculations are additionally hampered by a lack of data on the efficiency of fertilisation under natural conditions. Four distinct sources are used to justify quantitative claims regarding embryo loss: (i) a hypothesis published by Roberts & Lowe in TheLancet  is widely cited but has no practical quantitative value; (ii) life table analyses give consistent assessments of clinical pregnancy loss, but cannot illuminate losses at earlier stages of development; (iii) studies that measure human chorionic gonadotrophin (hCG) reveal losses in the second week of development and beyond, but not before; and (iv) the classic studies of Hertig and Rock offer the only direct insight into the fate of human embryos from fertilisation under natural conditions. Re-examination of Hertig's data demonstrates that his estimates for fertilisation rate and early embryo loss are highly imprecise and casts doubt on the validity of his numerical analysis. A recent re-analysis of hCG study data concluded that approximately 40-60% of embryos may be lost between fertilisation and birth, although this will vary substantially between individual women. In conclusion, natural human embryo mortality is lower than often claimed and widely accepted. Estimates for total prenatal mortality of 70% or higher are exaggerated and not supported by the available data.

Recurrent pregnancy losses and gestational age are closely related: an observational cohort study on 759 pregnancy losses

To assess the accurate dating of the cessation of pregnancy in patients with recurrent pregnancy loss (RPL) and to evaluate the incidence and recurrence rate of pregnancy losses in similar gestational age. In a retrospective cohort study, couples with history of RPL and availability of precise documentation regarding previous pregnancy losses were included. The vast majority of losses occurred within the first trimester. In patients experiencing more than 2 miscarriages in the same gestational stage, a tendency for recurrent losses around the same period of gestation was observed. Overall, the probability of losses at different gestational stages goes down with increasing number of miscarriages at the same stage. The study supports the need to ascertain data regarding the timing of pregnancy loss as accurately as possible for prognosis of future pregnancies and management of couples. A classification for unexplained RPL based on gestational age of miscarriages could help researchers to better investigate RPL.

Non-visualized pregnancy losses are prognostically important for unexplained recurrent miscarriage

STUDY QUESTION

Are non-visualized pregnancy losses (biochemical pregnancy loss and failed pregnancy of unknown location combined) in the reproductive history of women with unexplained recurrent miscarriage (RM) negatively associated with the chance of live birth in a subsequent pregnancy?

SUMMARY ANSWER

Non-visualized pregnancy losses contribute negatively to the chance for live birth: each non-visualized pregnancy loss confers a relative risk (RR) for live birth of 0.90 (95% CI 0.83; 0.97), equivalent to the RR conferred by each additional clinical miscarriage.

WHAT IS KNOWN ALREADY

The number of clinical miscarriages prior to referral is an important determinant for live birth in women with RM, whereas the significance of non-visualized pregnancy losses is unknown.

STUDY DESIGN, SIZE, DURATION

A retrospective cohort study comprising 587 women with RM seen in a tertiary RM unit 2000-2010. Data on the outcome of the first pregnancy after referral were analysed for 499 women.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study was conducted in the RM Unit at Rigshospitalet, Copenhagen, Denmark. We included all women with unexplained RM, defined as ≥3 consecutive clinical miscarriages or non-visualized pregnancy losses following spontaneous conception or homologous insemination. The category 'non-visualized pregnancy losses' combines biochemical pregnancy loss (positive hCG, no ultrasound performed) and failed PUL (pregnancy of unknown location, positive hCG, but on ultrasound, no pregnancy location established). Demographics were collected, including BMI, age at first pregnancy after referral and outcome of pregnancies prior to referral. Using our own records and records from other Danish hospitals, we verified the outcome of the first pregnancy after referral. For each non-visualized pregnancy loss and miscarriage in the women's reproductive history, the RR for live birth in the first pregnancy after referral was determined by robust Poisson regression analysis, adjusting for risk factors for negative pregnancy outcome.

MAIN RESULTS AND THE ROLE OF CHANCE

Non-visualized pregnancy losses constituted 37% of reported pregnancies prior to referral among women with RM. Each additional non-visualized pregnancy loss conferred an RR for live birth of 0.90 (95% CI 0.83; 0.97), which was not statistically significantly different from the corresponding RR of 0.87 (95% CI 0.80; 0.94) conferred by each clinical miscarriage. Among women with ≥2 clinical miscarriages, a reduced RR for live birth was also shown: 0.82 (95% CI 0.74; 0.92) for each clinical miscarriage and 0.89 (95% CI 0.80; 0.98) for each non-visualized pregnancy loss, respectively. Surgically treated ectopic pregnancies (EPs) were significantly more common for women with primary RM and no confirmed clinical miscarriages, compared with women with primary RM and ≥1 clinical miscarriage (22 versus 6%, difference 16% (95% CI 9.1%; 28.7%); RR for ectopic pregnancy was 4.0 (95% CI 1.92; 8.20).

LIMITATIONS, REASONS FOR CAUTION

RM was defined as ≥3 consecutive pregnancy losses before 12 weeks' gestation, and we included only women with unexplained RM after thorough evaluation. It is uncertain whether the findings apply to other definitions of RM and among women with known causes for their miscarriages.

WIDER IMPLICATIONS OF THE FINDINGS

To our knowledge, this is the first comprehensive investigation of prior non-visualized pregnancy losses and their prognostic significance for live birth in a subsequent pregnancy in women with unexplained RM. We show that a prior non-visualized pregnancy loss has a negative prognostic impact on subsequent live birth and is thus clinically significant.

STUDY FUNDING/COMPETING INTEREST(S)

None.

TRIAL REGISTRATION NUMBER

N/A.

Molecular aspects of implantation failure

Despite expanding global experience with advanced reproductive technologies, the majority of IVF attempts do not result in a successful pregnancy, foremost as a result of implantation failure. The process of embryo implantation, a remarkably dynamic and precisely controlled molecular and cellular event, appears inefficient in humans and is poorly understood. However, insights gained from clinical implantation failure, early pregnancy loss, and emerging techologies that enable molecular interrogation of endometrial-embryo interactions are unravelling this major limiting step in human reproduction. We review current molecular concepts thought to underlie implantation failure, consider the contribution of embryonic and endometrial factors, and discuss the clinical value of putative markers of impaired endometrial receptivity. Finally we highlight the nature of the dialogue between the maternal endometrium and the implanting embryo and discuss the concept of natural embryo selection. This article is part of a Special Issue entitled: Molecular Genetics of Human Reproductive Failure.

Sexual desire during the menopausal transition and early postmenopause: observations from the Seattle Midlife Women's Health Study

AIMS

To describe levels of sexual desire across the menopausal transition (MT) and early postmenopause (PM), including effects of age, MT-related factors, health, stress, symptoms (hot flash, sleep, mood), and social opportunity factors.

METHODS

A subset of Seattle Midlife Women's Health Study (SMWHS) participants who provided data during the early reproductive, early and late menopausal transition stages, or postmenopause (n = 286), including menstrual calendars for staging the MT, annual health reports between 1990 and 2005, and morning urine samples assayed for estrone glucuronide (E(1)G), testosterone (T), and follicle-stimulating hormone (FSH) was included. Multilevel modeling using the R program was used to test factors related to sexual desire.

RESULTS

Women experienced a significant decrease in sexual desire during the late MT stage (p < 0.01) and early PM (p < 0.0001). Those with higher urinary E(1)G and T reported significantly higher levels of sexual desire, whereas those with higher FSH levels reported significantly lower sexual desire (p < 0.0001, 0.06, and 0.0002, respectively). Women using hormone therapy also reported higher sexual desire (p = 0.02). Those reporting higher perceived stress reported lower sexual desire (p < 0.0001), but history of sexual abuse did not have a significant effect. Those most troubled by symptoms of hot flashes, fatigue, depressed mood, anxiety, difficulty getting to sleep, early morning awakening, and awakening during the night also reported significantly lower sexual desire (p range from <0.03 to 0.0001), but there was no effect of vaginal dryness. Women with better perceived health reported higher sexual desire (p < 0.0001), and those reporting more exercise and more alcohol intake also reported greater sexual desire (p < 0.0001). Having a partner was associated with lower sexual desire.

CONCLUSIONS

Clinicians working with women traversing the MT should be aware that promoting healthy sexual functioning among midlife women requires consideration of their changing biology as well as ongoing life challenges.

Symptom clusters during the late menopausal transition stage: observations from the Seattle Midlife Women's Health Study

OBJECTIVE

The aims of this study were to identify groups of women in the late menopausal transition stage who experienced the same cluster of symptoms and to identify indicators that predicted membership in these distinct groups.

METHODS

The sample consisted of a subset of Seattle Midlife Women's Health Study participants who were in the late menopausal transition stage and provided self-report data on symptoms experienced between 1990 and 2005. Latent class analysis (LCA) was used to identify groups of women who experienced similar clusters of the following five symptoms: problem concentrating, hot flashes, joint ache, mood changes, and awakening at night. LCA with multivariate logistic regression was used to identify covariates that predicted membership in each group.

RESULTS

Four groups of women were identified: (1) low severity for all symptoms except for joint ache, which was moderate (65%); (2) high severity for all symptoms except for hot flashes, which was moderate (13%); (3) high severity for hot flashes, joint ache, and awakening at night (12%); and (4) high severity for problem concentrating and joint ache (10%). A clear delineation between groups based on individual characteristics was not fully elucidated.

CONCLUSIONS

This analysis demonstrates that LCA may be useful to identify women who may experience poorer outcomes related to a higher propensity for severe symptoms. Shifting the focus from single symptoms to symptom clusters will aid in the identification of phenotypic profiles, thus facilitating symptom management strategies that can be tailored to meet the needs of individual women.

Is the menopausal transition stressful? Observations of perceived stress from the Seattle Midlife Women's Health Study

OBJECTIVE

To describe changes in the levels of perceived stress in relation to menopausal transition (MT)-related factors (MT stage, hot flash severity, urinary estrone glucuronide, urinary follicle-stimulating hormone, hormone therapy), aging and age-related changes, and psychosocial factors (income adequacy, role burden, social support, parenting, employment, history of sexual abuse, depressed mood).

DESIGN

A subset of participants (N = 418) in the longitudinal Seattle Midlife Women's Health Study provided data during the late reproductive and early and late MT stages or early postmenopause (PM) from 1990 to 2005, including menstrual calendars for staging the MT, annual health reports, and first morning urine specimens (assayed for estrone and follicle-stimulating hormone). Multilevel modeling was used to test patterns of perceived stress related to MT-related and aging-related factors and psychosocial factors with as many as 1,814 observations from 418 women per factor. Age was centered at 47.9 years.

RESULTS

The effects of the MT-related factors were not significant, although the stress ratings decreased during PM by 0.11 units (P = 0.06). In analyses with age as a covariate and with each covariate added separately, employment was associated with significantly higher levels of stress (beta = 0.14, P < 0.0001), as was history of sexual abuse (beta = 0.11, P = 0.03) and depressed mood (beta = 0.02, P < 0.0001). Improvement in each of the factors of role burden, social support, and income adequacy was associated with significantly lower perceived stress (beta = -0.19, -0.13, and -0.10, respectively; P < 0.0001 for all). Negative appraisal of aging changes and perceived poorer health were both associated with significantly higher stress levels (beta = 0.08, P < 0.0001 for both) and depressed mood (beta = -0.02, P < 0.0001). A multivariate model included significant effects of employment, perceived health, and depressed mood (beta = 0.24, -0.04, and 0.02, respectively; P < 0.0001 for all).

CONCLUSIONS

Being employed, experiencing depressed mood, and perceiving one's health as poor were more important in women's evaluation of their daily stress than severity of hot flashes, MT-related factors, or other social factors. Clinicians working with women going through the MT should remain vigilant to the impact of social circumstances of women's lives, especially employment, as well as focusing on the psychosocial and endocrine features of this transition.

Quantitative determination of progesterones and corticosteroids in human urine using gas chromatography/mass spectrometry: application to pelvic organ prolapse patients

A quantitative analytical method using gas chromatography/mass spectrometry (GC/MS) to determine urinary concentrations of eight progesterones and corticosteroids has been developed. After enzymatic hydrolysis with beta-glucouronidase/arylsulfatase, urine samples were extracted by simple one-step solid-phase extraction. Obtained extracts were derivatized with a mixture of N-methyl-N-(trimethylsilyl)trifluoroacetamide/ammonium iodide/dithiothreitol and determined by GC/MS in selected ion monitoring mode to increase the sensitivity. d(4)-Cortisol and d(9)-progesterone were used as internal standards for two different steroid groups. The linear correlation coefficient was in the range of 0.9913 to 0.9998 and recoveries were over 80% for all compounds. Precision and accuracy were in the range of 0.9-18.1 and 84.1-118.7%, respectively. The limit of quantitation (LOQ) was 10 ng/mL for 11-deoxycorticosterone and 21-deoxycortisol and 5 ng/mL for all other analytes. The developed method was successfully applied on pelvic organ prolapsed patients (n = 10, age: 67.9 +/- 4.9) and post-menopausal (n = 10, age: 63.6 +/- 5.5) control women. Urinary levels of most progesterones and corticosteroids except 11-deoxycorticosterone decreased but only that of 17 alpha-hydroxyprogesterone significantly decreased in patients compared with the control groups. Thus, it is concluded that progesterones could be a factor in the pathogenesis of pelvic organ prolapse, and, among them, 17 alpha-hydroxyprogesterone could be a biomarker for pelvic organ prolapse.

Polymorphisms in the estrogen synthesis and metabolism pathways and symptoms during the menopausal transition: observations from the Seattle Midlife Women's Health Study

OBJECTIVE

The purpose of this study was to determine whether polymorphisms in the estrogen synthesis and metabolism pathways are associated with women's vasomotor symptom experiences during the menopausal transition.

DESIGN

In 2002, a subset of women enrolled in the Seattle Midlife Women's Health Study since 1990 (N = 174) provided a buccal smear for genotyping. Women were recruited by complete ascertainment of selected multiethnic neighborhoods in 1990. Participants were midlife women with a mean age of 53 years in 2005, well educated, employed, married, and represented a multiethnic population. Genotyping was done for the following polymorphisms: CYP1A1m2; CYP1B1*2 and CYP1B1*3; CYP17 5'UTR; CYP19 3'UTR; CYP19 (TTTA)n; including CYP19 7r and CYP19 7(r-3); CYP19 8r and CYP19 11r; and ESR1PvuII and ESR1XbaI. Women rated their vasomotor symptom severity in diaries on days 5, 6, and 7 of the menstrual cycle or on a constant date each month for women skipping periods. Menopausal transition stage was determined from daily menstrual calendars. First voided urine specimens provided several times each year were assayed for estrone glucuronide.

RESULTS

Women with the CYP19 11r polymorphism reported more severe and frequent hot flashes during the middle and late menopausal transition stages and postmenopause and higher E1G levels during middle and late stages. None of the other polymorphisms studied were related to hot flashes or to estrone glucuronide levels.

CONCLUSIONS

These findings suggest a possible role for CYP19 polymorphisms in estrogen levels and in vasomotor symptoms during the menopausal transition that warrants further study in larger and more diverse populations of women.

Relationship between follicle-stimulating hormone levels at the beginning of the human menstrual cycle, length of the follicular phase and excreted estrogens: the FREEDOM study

Although reproductive aging has been separately related to elevated FSH and shorter follicular phase (FP), the direct association between both parameters has not been investigated. Also, the exact effects of increased FSH on estrogen production are yet to be established.A large database of daily urinary concentrations of FSH, LH, and estrone 3-glucuronide (E1G) from 37 regularly menstruating women (median 11 cycles per patient) was used. Initial FSH levels (iFSH) were estimated as the mean value of d 1-5. The day of E1G take-off (ETO) was determined by an algorithm, and accordingly, the FP was divided into early (d 1 to ETO) and late (ETO+1 to LH peak). FP maximum and integrated E1G were calculated. Subjects were distributed according to their mean iFSH into three categories (</=5, >5 to 10, and >10 IU/liter). There was a gradual decrease in FP length with increasing category (15.2 +/- 3.8, 14.1 +/- 3.6, and 13 +/- 2.6 d, respectively; P < 0.0001). A similar effect occurred in early FP (7.5 +/- 4, 6.4 +/- 3.7, and 5.4 +/- 2.7; P < 0.0001); in contrast, late FP was unaffected (7.7 +/- 2.1, 7.7 +/- 2.1, and 7.6 +/- 2.4; P = 0.86). No consistent increase in E1G was found with advancing iFSH category; however, women with mean initial LH higher than 6 IU/liter had significantly elevated maximum (P < 0.0001) and integrated (P = 0.002) E1G.FP length decreases in parallel with increasing iFSH, with a selective effect on the early FP. Increased FSH does not affect E1G; however, elevated initial LH level was related to higher E1G.

Comparison between creatinine and pregnanediol adjustments in the retrospective analysis of urinary hormone profiles during the human menstrual cycle

Measurement of reproductive hormones in urine is a practical way of obtaining large amounts of information; however, there is still controversy on how to overcome problems derived from volume fluctuations between samples. Creatinine adjustment is a widely accepted solution, however, it introduces an extra cost, and large studies involving multiple sequential determinations would benefit from more economical solutions.

We determined the value of creatinine adjustment, and compared it with a mathematical method that uses the smoothed profile of pregnanediol (PdG) as a reference to adjust other hormonal markers. To do this, we investigated the effects on three major urinary reproductive hormonal markers (luteinizing hormone (LH), estrone 3-glucuronide (E1G) and PdG) in 17 complete menstrual cycles. Detection of the day of LH peak did not differ between raw and adjusted data. Creatinine adjustment reduced variation in pre-ovulatory E1G levels between individuals, though the effect was negligible within individuals. No significant differences were found regarding post-ovulatory PdG rise. Although creatinine adjustment significantly reduces variability, producing smoother profiles, an equivalent degree of smoothness is obtained using the PdG adjustment.

We conclude that under the current technology, for the retrospective study of urinary hormonal profiles in the human menstrual cycle, PdG adjustment is a valid alternative to creatinine.

Urinary reproductive hormone level differences between African American and Caucasian women of reproductive age

OBJECTIVE

To compare urinary levels of reproductive hormones in African American and Caucasian women.

DESIGN

Cross-sectional study.

SETTING

Ten United States Air Force (USAF) bases.

PATIENT(S)

African American (n = 33) and Caucasian (n = 65) women of reproductive age from a larger study of USAF women (n = 170).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Urinary endocrine end points: follicular luteinizing hormone (LH), preovulatory LH, level of LH surge peak, early follicular follicle stimulating hormone (FSH), follicular LH:FSH ratio, midluteal FSH, FSH rise before menses, early follicular estrone 3-glucuronide (E(1)3G), midfollicular E(1)3G, periovulatory E(1)3G peak, midluteal E(1)3G, early follicular pregnanediol 3-glucuronide (Pd3G), follicular Pd3G, rate of periovulatory Pd3G increase, E(1)3G:Pd3G on the day of luteal transition, slope of E(1)3G:Pd3G, and midluteal Pd3G.

RESULT(S)

Relative to Caucasians, African American women had significantly lower follicular phase LH:FSH ratios (mean +/- SD: 0.7 +/- 0.4 vs. 1.0 +/- 0.6), lower follicular phase Pd3G levels (1.0 +/- 0.5 vs. 1.2 +/- 0.8 microg/mg creatinine), and lower rates of periovulatory Pd3G increase (0.5 +/- 0.7 vs. 1.0 +/- 1.2 microg/mg creatinine).

CONCLUSION(S)

Findings of this analysis should be considered preliminary evidence of racial differences in hormone levels. Future studies are needed to determine whether these differences have clinical significance.

Urinary follicle-stimulating hormone peak as a biomarker for estimating the day of ovulation

OBJECTIVE

To evaluate urinary follicle-stimulating hormone (FSH) as a biomarker for the day of ovulation.

DESIGN

Prospective observational study.

SETTING

Clinical research center.

PATIENT(S)

Thirteen women were monitored with measurements of serum and urinary hormones and ovarian ultrasonography during 20 menstrual cycles. Data on urinary hormones and ultrasound evaluations from a total of 65 menstrual cycles from 42 women were analyzed.

INTERVENTION(S)

Blood and/or urine samples were collected daily. Daily transvaginal ultrasonography was used to detect follicular collapse.

MAIN OUTCOME MEASURE(S)

LH, FSH, and E(2) were measured in serum. FSH, estrone conjugates (E1C), and pregnanediol-3-glucuronide (PdG) were analyzed in urine. The day of luteal transition (DLT) was calculated using two algorithms.

RESULT(S)

In 20 cycles, the urinary FSH peak was closer to the day of follicular collapse (-0.85 days) than was the peak day of serum E(2) and the day of luteal transition, as calculated by one algorithm. The FSH peak was not closer to the day of follicular collapse than the peak values of urinary LH, serum FSH, or the day of luteal transition as calculated by a second algorithm. The most consistent correspondence between a hormone peak and ovulation was for serum E(2), serum FSH, serum LH, and urinary FSH. In 65 cycles for which urinary hormone data and ultrasound evaluations were available, the urinary FSH peak occurred within 1 day of follicular collapse in 97% of cycles.

CONCLUSION(S)

Urinary FSH is a useful biomarker for estimating the day of ovulation in population-based studies.

Urinary oestrogen patterns in long follicular phases

Long menstrual cycles have been associated with reduced risk of breast cancer and increased risk of osteoporosis. These observations have led to assumptions about the endogenous oestrogen exposure of women with long cycles. However, daily oestrogen profiles in long menstrual cycles have not been described. This paper examines daily urinary oestrogen profiles during the follicular phases of 416 conception and non-conception cycles. Women were aged 21-42 years, had no history of infertility and were not under treatment. Twenty-eight cycles were defined as long, with a follicular phase that lasted 24 days or more. Five patterns were observed among these long cycles, the most common being a pattern consistent with delayed emergence of a dominant follicle. Other patterns were a pattern consistent with demise and replacement of a dominant follicle, one consistent with delayed follicular recruitment, one showing a prolonged initial drop in oestrogen and one with an extended oestrogen peak. Average follicular phase oestrogen concentrations were highest in cycles with short follicular phases (7-11 days). Oestrogen concentrations from long follicular phases (24-59 days) did not differ substantially from follicular phases of usual length (12-17 days). The oestrogen profiles in long follicular phases are heterogeneous and not necessarily hypo-oestrogenic.

Preimplantation urinary hormone profiles and the probability of conception in healthy women

OBJECTIVE

To examine hormonal predictors of conception in menstrual cycles from normal women.

DESIGN

Longitudinal study.

SETTING

Community.

PATIENT(S)

Two hundred fifteen healthy female volunteers with no known fertility problems who were trying to conceive.

INTERVENTION(S)

Participants recorded menstrual bleeding, sexual intercourse, and collected first morning urine specimens daily from when they stopped contraception until they became pregnant or for 6 months if no clinical pregnancy was achieved. Measurements were made of urinary LH and urinary metabolites of estrogen and progesterone.

MAIN OUTCOME MEASURE(S)

Conception was identified by a sensitive and specific immunoradiometric assay for urinary hCG.

RESULT(S)

Statistical analyses of 189 conception and 409 nonconception cycles controlled for sexual intercourse and interdependence of cycles from the same woman. Conception was more likely in cycles with lower baseline progesterone metabolite levels, higher ovulatory LH, and higher midluteal progesterone. Midluteal estrogen also was elevated in conception cycles when examined without adjusting for other hormone levels, but this finding did not persist after multivariate adjustment.

CONCLUSIONS

Menstrual cycles in normal women vary in their hormonal quality in ways that are predictive of cycle fertility.

Research on physiological and physical concomitants of caregiving: where do we go from here?

This article discusses the current state of research on the physiological and physical concomitants of caregiving. We offer recommendations about theoretical, empirical, and treatment issues that researchers should consider in future investigations. Important theoretical issues include specifying acute and chronic stress in caregiving research. Empirical issues include sample selection, home versus clinic assessments, the use of experimental probes, moderating and mediating variables, and measurement issues (problems with self-report of health, medical records, physical exams, and lab assessments). Finally, we note that investigators should use this newfound knowledge to target interventions to specific subsets of vulnerable caregivers. In this way, basic research into caregiving, as a model of chronic human stress, can provide more focused approaches to benefit both caregivers and patients.

A follow-up study of environmental and biologic determinants of fertility among 430 Danish first-pregnancy planners: design and methods

This paper presents design and methods of a follow-up study of fecundability (defined as the probability of conception during one menstrual cycle) in first-pregnancy planners. We recruited 430 couples by postal letter among 52,255 members of four trade unions. Couples without earlier reproductive experience were enrolled when they discontinued contraception and were followed in six complete menstrual cycles or until a pregnancy was recognized. Data included daily recordings of coitus and menstrual bleeding. Blood, semen, and urine specimens were collected to assess endocrine profile, semen quality, occult embryonal loss, and occupational exposures. Information was obtained about 1661 menstrual cycles (94% of expected). The proportion of couples obtaining a clinical pregnancy during 6 months of follow-up was 65%, and the average probability to obtain a pregnancy across all cycles was 16% (95% CI 14-18%). Among all conceptions the proportion of early embryonal loss was 17% (95% CI 12-22%). This study demonstrates the feasibility of a prospective study of fertility and that the established study base can provide useful information on environmental risk to subfertility.

Assessment of reproductive disorders and birth defects in communities near hazardous chemical sites. II. Female reproductive disorders

Members of the workgroup on female reproductive disorders discussed methods to evaluate five principal functions: menstrual dysfunction, infertility, pregnancy loss, lactation disorders, and pregnancy complications. To test each function, a nested strategy was considered, based on progressive levels of effort available to conduct field investigations. This strategy was analogous to the three-tier classification of biomarkers used by other workshops. The lowest level of effort, corresponding to Tier 1, consists only of questionnaires, diaries, and reviews of maternal and infant medical records. The medium level of effort (Tier 2) collects data from questionnaires and diaries, and some biologic specimens. Suggested laboratory analyses included measurement of progesterone in saliva and several glycoprotein hormones in urine that evaluate menstrual dysfunction, infertility, and pregnancy loss. The highest level of effort (Tier 3) involves prospective collection of diary information and simultaneous collection of biological specimens.

Menstrual cycle hormonal profiles of women with and without premenstrual syndrome

This paper compares the urinary hormone profiles of estrogen and pregnanediol in women with documented premenstrual syndrome (PMS) (n = 65) and asymptomatic volunteers (n = 18). Daily 24-h urine samples were collected for an entire menstrual cycle. Subject groups did not differ significantly in menses length or in the day of the preovulatory estrogen peak. Cycle length was significantly shorter for the volunteers (p < 0.05). The day of the pregnanediol peak occurred significantly later for the PMS patient group than for the asymptomatic volunteers (p < 0.05). Split plot analysis of variance showed no significant differences overall between subject groups for levels of urinary estrogen or pregnanediol. This study did not find evidence of progesterone deficiency amongst sufferers of the premenstrual syndrome.

Using the ratio of urinary oestrogen and progesterone metabolites to estimate day of ovulation

We have developed a method of estimating day of ovulation using urinary ovarian hormone data. The method identifies a day of luteal transition that occurs at the shift from production of follicular oestrogen to luteal progesterone. The algorithm for identifying this shift was evaluated and judged better than specified alternatives in that it resulted in (1) a high concordance between the day of luteal transition and peaks in urinary luteinizing hormone (LH) for cycles with well-defined peaks, (2) a low variance in the length of the luteal phase of the menstrual cycle, which presumably reflects a low measurement error in estimating day of ovulation, and (3) a high proportion of cycles for which an approximate day of ovulation could be determined. To validate the new algorithm, it was applied to an independent data set. The algorithm identified a day of luteal transition in 88 per cent of these cycles, and the identified day occurred within two days of the urinary LH peak for all the cycles with clear LH peaks. Determination of the day of luteal transition to estimate ovulation requires only first-morning urine specimens, requires no correction for day-to-day variations in urine concentration, and can be applied to a mid-cycle window of data.

Using reproductive effect markers to observe subclinical events, reduce misclassification, and explore mechanism

Biological markers of effect, in general less widely available than exposure markers, do exist in the field of reproduction and increasingly are being used in epidemiological studies. Several such markers, including semen quality, menstrual hormones, early pregnancy loss, and placental abnormalities, are cited as examples. We argue the value of effect markers for detecting subclinical events that are critical for reproductive performance. Such studies can extend knowledge of the true frequency and determinates of reproductive disorders. A second portion of the paper deals with the role of effect markers in reducing disease misclassification. With a hypothetical early pregnancy study as a case in point, we illustrate the degree and direction of bias associated with several different protocols and encourage epidemiologists to weigh these quantitative considerations in deciding on study design. Finally, we discuss uses of biological markers to explore mechanisms, drawing on experience in an ongoing reproductive study that is testing a hypothetical pathway from maternal psychosocial stress to reduced fetal growth using urine catecholamine levels as a physiological marker of exposure and placental vascular abnormalities as a marker of effect.

Caffeinated beverages and decreased fertility

104 healthy women who had been attempting to become pregnant for three months were interviewed about their use of caffeinated beverages, alcohol, and cigarettes. In their subsequent cycles, women who consumed more than the equivalent of one cup of coffee per day were half as likely to become pregnant, per cycle, as women who drank less. A dose-response effect was present.

Incidence of early loss of pregnancy

We studied the risk of early loss of pregnancy by collecting daily urine specimens from 221 healthy women who were attempting to conceive. Urinary concentrations of human chorionic gonadotropin (hCG) were measured for a total of 707 menstrual cycles with use of an immunoradiometric assay that is able to detect hCG levels as low as 0.01 ng per milliliter, with virtually 100 percent specificity for hCG in the presence of luteinizing hormone. Our criterion for early pregnancy--an hCG level above 0.025 ng per milliliter on three consecutive days--was determined after we compared the hCG levels in the study group with the levels in a comparable group of 28 women who had undergone sterilization by tubal ligation. We identified 198 pregnancies by an increase in the hCG level near the expected time of implantation. Of these, 22 percent ended before pregnancy was detected clinically. Most of these early pregnancy losses would not have been detectable by the less sensitive assays for hCG used in earlier studies. The total rate of pregnancy loss after implantation, including clinically recognized spontaneous abortions, was 31 percent. Most of the 40 women with unrecognized early pregnancy losses had normal fertility, since 95 percent of them subsequently became clinically pregnant within two years.