Prospectively assessed menstrual cycle characteristics in female wafer-fabrication and nonfabrication semiconductor employees

Women aged 18–44 years in silicon-wafer fabrication-room (fab) jobs and frequency-MAtched women in nonfab jobs were screened for a prospective study of reproductive health (n = 2,639). Among the 739 (28%) eligible women, 481 (65%) completed a baseline interview; 402 completed at least one menstrual cycle of follow-up with daily diaries and urinary assays to exclude conceptive cycles. Adjusted mean cycle lengths (MCL) did not differ between fab and nonfab women (p = 0.97). Women working in thin film and ion implantation (TFII) had the highest adjusted MCL (34.8 ± 1.7 days) compared with nonfab workers (32.5 ± 1.4 days, p = 0.07). Among women working exclusively in one group, TFII women had significantly higher MCL (36.1 ± 2.04 days) than nonfab women (32.0 ± 1.38 days, p = 0.017). TFII women were also more likely to have all cycles >35 days (adjusted relative risk [RR] = 2.45; 95% CI = 0.85-6.06). Variability was assessed by logarithmic transformation of the mean standard deviation (MLSD) in cycle length per woman and adjusted for age and ethnicity (4.5 days for fab vs. 4.0 days for nonfab, p = 0.16). Women working exclusively in TFII or photolithography (PHOTO) had significantly higher adjusted MLSD in cycle length (6.68 ± 1.28 and 5.72 ± 1.24 days, respectively) than women in nonfab (4.1 ± 1.16 days, p = 0.013 and 0.019, respectively). Fab and nonfab women did not differ significantly in mean days of bleeding or risk of having cycles >35 or <24 days. However, elevated risks of having cycles <24 days were seen in supervisor engineers (adjusted RR = 2.46, 95% CI = 1.19-3.63) and PHOTO women (adjusted RR = 1.83, 95% CI = 0.94-2.88).     

Menstrual patterns and risk of adult-onset diabetes mellitus

We examined the association between menstrual patterns and risk of developing adult-onset diabetes in a prospective study of 668 white, college-educated women who completed menstrual diaries throughout their reproductive years. We calculated summary measures of cycle length and variability and bleeding duration for ages < or = 22, 23-27, 28-32, and 33-37 years. The analysis included 35,418 person-years of follow-up and 49 self-reported cases of diabetes (median age at diagnosis, 63 years). There was no association between diabetes risk and age at menarche, mean cycle length, cycle variability, or frequency of long cycles (> 42 days). Longer bleeding periods in the mid- and late reproductive years were somewhat associated with an increased risk of diabetes (adjusted rate ratio 1.4, 95% confidence interval 1.0-1.8 per day increase in bleeding duration for menses during ages 28-32). These results do not support the association of long or irregular menstrual cycles with post-menopausal diabetes incidence, but do suggest a possible association of longer bleeding duration with subsequent onset of diabetes.     

Physical activity and menstrual cycle characteristics in two prospective cohorts

Relations between physical activity and prospectively collected menstrual cycle characteristics were examined in two large cohorts. One cohort consisted of women employed in the semiconductor industry in 1989 who participated in a prospective study of reproductive outcomes (n = 367). The other consisted of women living in Tecumseh, Michigan, who completed both the 1992-1993 and 1993-1994 examinations for the Michigan Bone Health Study (n = 328). Mean cycle length, variability of cycle length, and mean bleed length were calculated from daily diaries (Semiconductor cohort) or monthly menstrual calendars (Michigan cohort) for a median of five and 11 cycles, respectively. Physical activity was assessed by self-report at baseline and expressed as metabolic equivalent-minutes per week. In the Semiconductor study, women also reported daily minutes of vigorous exercise in their diaries. In the Michigan cohort, total physical activity, total recreational physical activity, and vigorous recreational activity were positively associated with cycle length. The magnitude of these associations declined as body mass index increased. In the Semiconductor cohort, the minutes of daily vigorous exercise were positively associated with cycle length only in a repeated-measures analysis. These findings lend modest support to the hypothesis that moderate levels of physical activity can lengthen the menstrual cycle.     

Accuracy of reporting of menstrual cycle length

There are many studies based on self-reported menstrual cycle length, yet little is known about the validity of this measure. The authors used data collected in 1990 from 352 women born in Chicago, Illinois, aged 37-39 years. Women reported their usual cycle length and behavioral and reproductive characteristics at study enrollment and then completed daily menstrual diaries for up to 6 months. The authors compared this observed cycle length (geometric mean) with the reported length by using kappa coefficients. To assess systematic effects, they performed linear regression of the difference between reported and observed cycle length. Agreement between observed and reported cycle length was moderate. The crude overall kappa coefficient was 0.33; the kappa adjusted for within-woman sampling variability was 0.45 (95% confidence interval: 0.36, 0.55). On average, women overestimated their cycle length by 0.7 days (95% confidence interval: 0.3, 1.0). Reporting by sexually active women and women with a history of infertility was more accurate. Parity, body mass index, prior medical evaluation for irregular cycles, and exercise were all associated with systematic reporting differences. Studies that rely on self-reported cycle length could be prone to artifactual findings because of systematic covariate effects on reporting.     

Menstrual cycle variability and the likelihood of achieving pregnancy

The menstrual cycle is an important indicator of underlying hormonal function. Although menstrual cycle variability (sometimes referred to as 'regularity') is associated with a variety of demographic, behavioral, occupational, and environmental factors, as well as with several chronic diseases, few studies have examined its association with fecundity. We investigated whether a woman's menstrual cycle variability was associated with the likelihood of her achieving pregnancy. In this prospective study, we analyzed 3,536 menstrual cycles from 401 women (aged 19-41) recruited from 1990-1994. The women provided daily diaries recording menstrual bleeding, intercourse, and birth control use. Urine samples were assayed for human chorionic gonadotropin to identify early pregnancies during each menstrual cycle. Each woman's menstrual cycle variability was defined by the standard deviation of her cycle lengths during followup. The median follow-up was eight cycles. The outcome was her per-cycle probability of pregnancy. We found that women with high menstrual cycle variability had a reduced (51% lower) per cycle probability of pregnancy (fecundity ratio: 0.49; 95% confidence interval: 0.31, 0.77) compared with women with minimal variability. This relationship was independent of a woman's age and her mean cycle length. Thus, researchers and clinicians using menstrual cycle characteristics as indicators of endocrine or reproductive health should include measures of cycle variability in addition to the more commonly examined cycle length.     

Hormonal levels among HIV-1-seropositive women compared with high-risk HIV-seronegative women during the menstrual cycle. Women's Health Study (WHS) 001 and WHS 001a Study Team

There is a paucity of normative data on hormonal levels among HIV-infected women. Hormonal levels may influence fertility and HIV-related immunological and virological factors. The objective of this study was to determine progesterone and estradiol levels during the menstrual cycle in HIV-seropositive women compared with high-risk seronegative women. The study enrolled 55 HIV-infected and 10 high-risk uninfected women with self-reported regular menstrual cycles (25-30-day cycles). Progesterone and estradiol levels were determined on a weekly basis for 8 weeks. The analysis included evaluations from the first complete menstrual cycle for the 54 HIV-infected and 9 uninfected women who had at least one complete cycle. The median age was 35 years for HIV-infected women and 36 years for uninfected women. The median CD4+ count for HIV-seropositive women was 210 cells/mm3. The median menstrual cycle length was 28 days (range 22-49 days) for HIV-infected women and 25 days (range 24-44 days) for uninfected women. The maximum progesterone level during the luteal phase was normal (>3.0 ng/ml) for 52 (96%) of 54 HIV-seropositive women and 7 (78%) of 9 HIV-seronegative women (p = 0.09, Fisher's exact test). The median maximum progesterone level was 12.2 ng/ml in HIV-seropositive women and 7.2 ng/ml in HIV-seronegative women (p = 0.07, Wilcoxon test). The median maximum estradiol value during the follicular phase was 148 pg/ml for HIV-seropositive women and 111 pg/ml for HIV-seronegative women (p = 0.04, Wilcoxon test). Among HIV-infected women, there were no significant differences in progesterone and estradiol levels by antiretroviral therapy, baseline plasma viral load, or median CD4+ cell count. We conclude that HIV-infected women with self-reported normal menstrual cycles have normal levels of progesterone and estradiol during the menstrual cycle.     

Menstrual and reproductive characteristics and age at natural menopause

Data from women who enrolled between 1935 and 1939 in a long-term prospective study of menstrual and reproductive health, in which menstrual cycles and other events were recorded as they occurred, were analyzed to examine factors associated with age at natural menopause. Analysis was restricted to 561 women who enrolled before age 25 years and recorded data through at least age 44 years. Women with a median cycle length that was less than 26 days at ages 20-35 years reached menopause 1.4 years earlier than those with cycles between 26 and 32 days. The difference in mean menopausal age between women with short cycle length (less than 26 days) and women with long cycle length (33 days or longer) was 2.2 years. Women who had ever been pregnant reached menopause slightly, but statistically significantly, later than women who had never been pregnant. Similarly, women who had ever had a live birth had a slightly later age at menopause compared with nulliparous women. A trend of later age at menopause with increasing parity was also observed. There was no association with age at menarche. Certain of these observations are consistent with proposed mechanisms of cessation of menstrual function.     

Menstrual cycle characteristics and reproductive hormone levels in women exposed to atrazine in drinking water

Atrazine is the most commonly used herbicide in the U.S. and a wide-spread groundwater contaminant. Epidemiologic and laboratory evidence exists that atrazine disrupts reproductive health and hormone secretion. We examined the relationship between exposure to atrazine in drinking water and menstrual cycle function including reproductive hormone levels.Women 18–40 years old residing in agricultural communities where atrazine is used extensively (Illinois) and sparingly (Vermont) answered a questionnaire (n=102), maintained menstrual cycle diaries (n=67), and provided daily urine samples for analyses of luteinizing hormone (LH), and estradiol and progesterone metabolites (n=35). Markers of exposures included state of residence, atrazine and chlorotriazine concentrations in tap water, municipal water and urine, and estimated dose from water consumption.Women who lived in Illinois were more likely to report menstrual cycle length irregularity (odds ratio (OR)=4.69; 95% confidence interval (CI): 1.58–13.95) and more than 6 weeks between periods (OR=6.16; 95% CI: 1.29–29.38) than those who lived in Vermont. Consumption of >2 cups of unfiltered Illinois water daily was associated with increased risk of irregular periods (OR=5.73; 95% CI: 1.58–20.77). Estimated “dose” of atrazine and chlorotriazine from tap water was inversely related to mean mid-luteal estradiol metabolite. Atrazine “dose” from municipal concentrations was directly related to follicular phase length and inversely related to mean mid-luteal progesterone metabolite levels.We present preliminary evidence that atrazine exposure, at levels below the US EPA MCL, is associated with increased menstrual cycle irregularity, longer follicular phases, and decreased levels of menstrual cycle endocrine biomarkers of infertile ovulatory cycles.     

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.     

How regular is regular? An analysis of menstrual cycle regularity

We performed a retrospective analysis to ascertain how accurately women who believe that they have regular menstrual cycles estimate the length of their actual cycles. Data were extracted from a chart review of subjects from three different studies of barrier contraceptives. Subjects were between 18 and 40 years of age and reported "regular" prestudy menstrual cycles with a consistent cycle length between 21 and 35 days. Participants prospectively recorded their menses for the up to 30 weeks. Each subject's estimated cycle length was compared to the average of her actual cycle lengths and the range and variability in each individual's cycle length was calculated. A total of 786 cycles from 130 women who recorded 4 or more cycles were analyzed. The averages of the participants' estimated cycle lengths was similar to the prospective averages of their actual cycle lengths (29.0 +/- 2.7 days vs. 29.1 +/- 3.5 days, respectively, p = 0.8). Forty-six percent of all subjects had a cycle range of 7 days or more, and 20% had a cycle range of 14 days or more. The average length of menses was 5.2 +/- 1.0 days. When evaluating only women with cycle lengths from 21 to 35 days, the average length of menses was positively associated with the average actual cycle length (p = 0.04). Although the average of a woman's menstrual cycles compares favorably to her impression of her cycle length, the variability in menstrual cycle lengths is significant. This variation may have clinical impact on contraceptive practice, contraceptive research studies and pregnancy-related care.     

Validity of self-reported menstrual cycle length

PURPOSE: Self-reported menstrual cycle length has been associated with host and environmental factors and chronic disease risk. The purpose of this study is to evaluate the validity of self-reported cycle length. METHODS: The authors assessed the agreement between a woman's self-reported "usual" cycle length at study onset with the mean of her observed cycle lengths from prospective daily diaries for 398 women aged 19 to 41 years in the Mount Sinai Study of Women Office Workers (1990 to 1994). RESULTS: Forty-three percent of women self-reported usual cycle lengths more than 2 days different from their mean length. When self-reported cycle length was categorized (<26, 26 to 35, and >35 days) and compared with mean cycle length, 21% of women were misclassified. Women who were older, married, and with higher income were more likely to have accurately reported their menstrual cycle length. Women who had short or long mean cycle lengths (lowest and highest quintile of length) were less likely to self-report accurately, and accuracy decreased monotonically with increasing cycle variability. CONCLUSIONS: These findings show considerable measurement error in self-reported cycle length, as well as describe population subgroups that report menstrual cycle length with the greatest accuracy.     

Hot flashes in the late reproductive years: risk factors for Africa American and Caucasian women

Hot flashes are a primary reason that midlife women seek medical care, but there is little information about the onset or the predictors of hot flashes in the years before the menopause. This study examines women's experience of hot flashes in the late reproductive years, comparing African American and Caucasian women, and identifies hormonal, behavioral, and environmental risk factors for hot flashes associated with ovarian aging. Data are from a population-based prospective cohort study of ovarian aging in women who were ages 35--47, in general good health, and had regular menstrual cycles at study enrollment. Hot flashes were assessed by subject report in a structured interview at the first follow-up period and correlated highly with previous prospective daily ratings of hot flashes (p = 0.0001). Blood samples were obtained in the first 6 days of the menstrual cycle in two consecutive cycles at enrollment and two consecutive cycles at follow-up. Predictor variables include hormone measures, structured interview, and standard questionnaire data. Thirty-one percent of the sample (n = 375) reported hot flashes (mean age 41 years). In bivariate analysis, more African American than Caucasian women reported hot flashes (38% vs. 25%, p = 0.01). Significant predictors of hot flashes in the final multivariable logistic regression model were higher follicle-stimulating hormone (FSH) levels (odds ratio [OR] 3.19), anxiety (OR 1.06), baseline menopausal symptoms (OR 4.91), alcohol use (OR 1.09), body mass index (BMI) (OR 1.04), and parity (OR 1.20). Race did not predict hot flashes after adjusting for these variables. Hot flashes commonly occur before observable menstrual irregularities in the perimenopause and are associated with both hormonal and behavioral factors. The association of hot flashes with increased body mass (BMI) challenges the current "thin" hypothesis and raises important questions about the role of BMI in hormone dynamics in the late reproductive years.     

COVID-19 vaccination and menstrual cycle characteristics: A prospective cohort study

We prospectively examined the association between COVID-19 vaccination and menstrual cycle characteristics in an internet-based prospective cohort study. We included a sample of 1,137 participants who enrolled in Pregnancy Study Online (PRESTO), a preconception cohort study of couples trying to conceive, during January 2021-August 2022. Eligible participants were aged 21–45 years, United States or Canadian residents, and trying to conceive without fertility treatment. At baseline and every 8 weeks for up to 12 months, participants completed questionnaires on which they provided information on COVID-19 vaccination and menstrual cycle characteristics, including cycle regularity, cycle length, bleed length, heaviness of bleed, and menstrual pain. We fit generalized estimating equation (GEE) models with a log link function and Poisson distribution to estimate the adjusted risk ratio (RR) for irregular cycles associated with COVID-19 vaccination. We used linear regression with GEE to estimate adjusted mean differences in menstrual cycle length associated with COVID-19 vaccination. We adjusted for sociodemographic, lifestyle, medical and reproductive factors. Participants had 1.1 day longer menstrual cycles after receiving the first dose of COVID-19 vaccine (95 % CI: 0.4, 1.9) and 1.3 day longer cycles after receiving the second dose (95 % CI: 0.2, 2.5). Associations were attenuated at the second cycle post-vaccination. We did not observe strong associations between COVID-19 vaccination and cycle regularity, bleed length, heaviness of bleed, or menstrual pain. In conclusion, COVID-19 vaccination was associated with a ∼1 day temporary increase in menstrual cycle length, but was not appreciably associated with other menstrual cycle characteristics.     

Cigarette smoking and effects on hormone function in premenopausal women

Cigarette smoke contains compounds that are suspected to cause reproductive damage and possibly affect hormone activity; therefore, we examined hormone metabolite patterns in relation to validated smoking status. We previously conducted a prospective study of women of reproductive age (n = 403) recruited from a large health maintenance organization, who collected urine daily during an average of three to four menstrual cycles. Data on covariates and daily smoking habits were obtained from a baseline interview and daily diary, and smoking status was validated by cotinine assay.Urinary metabolite levels of estrogen and progesterone were measured daily throughout the cycles. For the present study, we measured urinary levels of the pituitary hormone follicle-stimulating hormone (FSH) in a subset of about 300 menstrual cycles, selected by smoking status, with the time of transition between two cycles being of primary interest. Compared with nonsmokers, moderate to heavy smokers (>/= 10 cigarettes/day) had baseline levels (e.g., early follicular phase) of both steroid metabolites that were 25-35% higher, and heavy smokers (>/= 20 cigarettes/day) had lower luteal-phase progesterone metabolite levels. The mean daily urinary FSH levels around the cycle transition were increased at least 30-35% with moderate smoking, even after adjustment. These patterns suggest that chemicals in tobacco smoke alter endocrine function, perhaps at the level of the ovary, which in turn effects release of the pituitary hormones. This endocrine disruption likely contributes to the reported associations of smoking with adverse reproductive outcomes, including menstrual dysfunction, infertility, and earlier menopause.     

A multicenter,randomized study of an extended cycle oral contraceptive

OBJECTIVE: To assess the efficacy and safety of Seasonale, 91-day extended cycle oral contraceptive (OC). METHODS: A parallel, randomized, multicenter open-label, 1-year study of the OC Seasonale [30 microg ethinyl estradiol (EE)/150 microg levonorgestrel (LNG), and Nordette-28 (30 microg EE/150 microg LNG)] in sexually active, adult women (18-40 years) of childbearing potential. Patients received either four 91-day cycles of extended cycle regimen OC, or 13 cycles of the conventional 28-day OC with daily monitoring of compliance and bleeding via electronic diaries. RESULTS: When taken daily for 84 days followed by 7 days of placebo, the extended cycle regimen was effective in preventing pregnancy and had a safety profile that was comparable to that observed with the 28-day OC regimen that served as the control. While unscheduled (breakthrough) bleeding was reported among patients treated with the extended cycle regimen, it decreased with each successive cycle of therapy and was comparable to that reported by patients who received the conventional OC regimen by the fourth extended cycle. CONCLUSION: This study demonstrated that Seasonale, 91-day extended cycle OC containing 84 days of 30 microg EE/150 microg LNG followed by 7 days of placebo, was effective, safe and well tolerated.     

Menstrual bleeding patterns among regularly menstruating women

Menstrual bleeding patterns are considered relevant indicators of reproductive health, though few studies have evaluated patterns among regularly menstruating premenopausal women. The authors evaluated self-reported bleeding patterns, incidence of spotting, and associations with reproductive hormones among 201 women in the BioCycle Study (2005-2007) with 2 consecutive cycles. Bleeding patterns were assessed by using daily questionnaires and pictograms. Marginal structural models were used to evaluate associations between endogenous hormone concentrations and subsequent total reported blood loss and bleeding length by weighted linear mixed-effects models and weighted parametric survival analysis models. Women bled for a median of 5 days (standard deviation: 1.5) during menstruation, with heavier bleeding during the first 3 days. Only 4.8% of women experienced midcycle bleeding. Increased levels of follicle-stimulating hormone (β = 0.20, 95% confidence interval: 0.13, 0.27) and progesterone (β = 0.06, 95% confidence interval: 0.03, 0.09) throughout the cycle were associated with heavier menstrual bleeding, and higher follicle-stimulating hormone levels were associated with longer menses. Bleeding duration and volume were reduced after anovulatory compared with ovulatory cycles (geometric mean blood loss: 29.6 vs. 47.2 mL; P = 0.07). Study findings suggest that detailed characterizations of bleeding patterns may provide more insight than previously thought as noninvasive markers for endocrine status in a given cycle.     

Abnormal bleeding patterns associated with menorrhagia in women in the community and in women presenting to primary care

BACKGROUND: There is an assumption that in women with menorrhagia 'excessive menstrual loss in regular cycles is the most common clinical presentation' yet epidemiological studies show irregular cycles and bleeding are common. OBJECTIVES: To test the hypothesis that, in women who present to primary care with menorrhagia, excessive menstrual loss in regular cycles is the most common clinical presentation, and to determine the frequency with which symptoms known to be associated with gynaecological malignancy occur. METHODS: A postal survey of all women aged 18-54 years was used to identify symptoms of vaginal bleeding in an urban general practice with 10 000 registered patients. Follow-up surveys were carried out at 6 and 12 months. Consultation data from general practice held records were gathered from baseline to 18 months. Women who consulted with increased vaginal bleeding during the 18-month study period were separately analysed according to their self-reported symptoms in the questionnaire completed in the 6 months prior to the consultation. RESULTS: At baseline, of the 736 women in the community identified with menorrhagia, 46% had at least one symptom of irregular vaginal bleeding. In the subgroup of 138 women with menorrhagia who consulted primary care with increased vaginal bleeding, the proportion with at least one symptom of irregular vaginal bleeding was 73%. CONCLUSION: In women with heavy menstrual bleeding, excessive menstrual loss in regular cycles is not the most common clinical presentation in primary care. Guidelines on menorrhagia should acknowledge the variety of symptoms that women with heavy menstrual bleeding present to primary care.     

Factors affecting menstrual cycle characteristics

This 1989-1991 study in California and Utah used daily urinary metabolites of estrogen and progesterone and computer algorithms to assess ovulatory status and day of ovulation. The authors examined the associations of risk factors with menstrual cycle characteristics for 309 working women aged 20-44 years who collected a median of five cycles each of daily urine samples. Linear mixed models were used to assess continuous menstrual outcomes. Compared with women less than age 35 years, women aged 35 years or older had a significantly decreased (-0.94 days, 95% confidence interval: -1.83, -0.05) adjusted mean cycle length. Age modified the effects of smoking, physical activity, ethnicity, and alcohol consumption on mean follicular phase length. Asian women had a significantly longer (1.65 days, 95% confidence interval: 0.54, 2.76) adjusted mean cycle length compared with Caucasian women. Compared with women who did not consume alcoholic drinks, women who did had a significantly shorter (-1.26 days, 95% confidence interval: -2.21, -0.31) adjusted mean cycle length. Mean cycle and phase lengths were significantly associated with length of the prior luteal phase. These results indicate that potentially modifiable risk factors, as well as immutable host factors, are associated with menstrual cycle characteristics that may in turn be related to subsequent disease risk.     

Feasibility study of the use of a daily electronic mail reminder to improve oral contraceptive compliance

Women who ingest their oral contraceptive pill (OCP) as part of a daily routine are more likely use their OCPs correctly. This trial examines the feasibility of an electronic-mail (e-mail) reminder system to improve OCP compliance. An e-mail reminder was sent to 50 new OCP users daily for 3 months. Subjects sent an e-mail reply to confirm receipt. OCP compliance was recorded on diaries. Four subjects were discontinued for not checking their e-mail. Active participants missed a median of 18% of the e-mail reminders (range: 0-65%). A follow-up visit was scheduled after completion of three OCP cycles. Of the 40 subjects returning completed diaries, 50% missed no active pills at all and 20% missed at least one in each cycle. Most found the daily e-mail somewhat (65%) or very helpful (19%) for OCP compliance. Of those continuing OCPs, 64% wanted to continue receiving e-mail reminders at the completion of the study. Because inconsistent OCP use is a significant cause of unplanned conception, the use of e-mail to improve OCP compliance has the potential to decrease unintended pregnancies.     

Chlorination by-products in drinking water and menstrual cycle function

We analyzed data from a prospective study of menstrual cycle function and early pregnancy loss to explore further the effects of trihalomethanes (THM) on reproductive end points. Premenopausal women ((italic)n(/italic) = 403) collected urine samples daily during an average of 5.6 cycles for measurement of steroid metabolites that were used to define menstrual parameters such as cycle and phase length. Women were asked about consumption of various types of water as well as other habits and demographics. A THM level was estimated for each cycle based on residence and quarterly measurements made by water utilities during a 90-day period beginning 60 days before the cycle start date. We found a monotonic decrease in mean cycle length with increasing total THM (TTHM) level; at > 60 microg/L, the adjusted decrement was 1.1 days [95% confidence interval (CI), -1.8 to -0.40], compared with less than or equal to 40 microg/L. This finding was also reflected as a reduced follicular phase length (difference -0.94 day; 95% CI, -1.6 to -0.24). A decrement in cycle and follicular phase length of 0.18 days (95% CI, -0.29 to -0.07) per 10 microg/L unit increase in TTHM concentration was found. There was little association with luteal phase length, menses length, or cycle variability. Examining the individual THMs by quartile, we found the greatest association with chlorodibromomethane or the sum of the brominated compounds. Incorporating tap water consumption showed a similar pattern of reduced cycle length with increasing TTHM exposure. These findings suggest that THM exposure may affect ovarian function and should be confirmed in other studies.