Characteristics of prospectively measured vaginal bleeding among women trying to conceive

Characteristics of menstrual cycles with or without intercourse in women with no known subfertility

STUDY QUESTION

Does sexual intercourse enhance the cycle fecundability in women without known subfertility?

SUMMARY ANSWER

Sexual intercourse (regardless of timing during the cycle) was associated with cycle characteristics suggesting higher fecundability, including longer luteal phase, less premenstrual spotting and more than 2 days of cervical fluid with estrogen-stimulated qualities.

WHAT IS KNOWN ALREADY

Human females are spontaneous ovulators, experiencing an LH surge and ovulation cyclically, independent of copulation. Natural conception requires intercourse to occur during the fertile window of a woman's menstrual cycle, i.e. the 6-day interval ending on the day of ovulation. However, most women with normal fecundity do not ovulate on Day 14, thus the timing of the hypothetical fertile window varies within and between women. This variability is influenced by age and parity and other known or unknown elements. While the impact of sexual intercourse around the time of implantation on the probability of achieving a pregnancy has been discussed by some researchers, there are limited data regarding how sexual intercourse may influence ovulation occurrence and menstrual cycle characteristics in humans.

STUDY DESIGN SIZE DURATION

This study is a pooled analysis of three cohorts of women, enrolled at Creighton Model FertilityCare centers in the USA and Canada: 'Creighton Model MultiCenter Fecundability Study' (CMFS: retrospective cohort, 1990-1996), 'Time to Pregnancy in Normal Fertility' (TTP: randomized trial, 2003-2006) and 'Creighton Model Effectiveness, Intentions, and Behaviors Assessment' (CEIBA: prospective cohort, 2009-2013). We evaluated cycle phase lengths, bleeding and cervical mucus patterns and estimated the fertile window in 2564 cycles of 530 women, followed for up to 1 year.

PARTICIPANTS/MATERIALS SETTING METHODS

Participants were US or Canadian women aged 18-40 and not pregnant, who were heterosexually active, without known subfertility and not taking exogenous hormones. Most of the women were intending to avoid pregnancy at the start of follow-up. Women recorded daily vaginal bleeding, mucus discharge and sexual intercourse using a standardized protocol and recording system for up to 1 year, yielding 2564 cycles available for analysis. The peak day of mucus discharge (generally the last day of cervical fluid with estrogen-stimulated qualities of being clear, stretchy or slippery) was used to identify the estimated day of ovulation, which we considered the last day of the follicular phase in ovulatory cycles. We used linear mixed models to assess continuous cycle parameters including cycle, menses and cycle phase lengths, and generalized linear models using Poisson regression with robust variance to assess dichotomous outcomes such as ovulatory function, short luteal phases and presence or absence of follicular or luteal bleeding. Cycles were stratified by the presence or absence of any sexual intercourse, while adjusting for women's parity, age, recent oral contraceptive use and breast feeding.

MAIN RESULTS AND THE ROLE OF CHANCE

Most women were <30 years of age (75.5%; median 27, interquartile range 24-29), non-Hispanic white (88.1%), with high socioeconomic indicators and nulliparous (70.9%). Cycles with no sexual intercourse compared to cycles with at least 1 day of sexual intercourse were shorter (29.1 days (95% CI 27.6, 30.7) versus 30.1 days (95% CI 28.7, 31.4)), had shorter luteal phases (10.8 days (95% CI 10.2, 11.5) versus 11.4 days (95% CI 10.9, 12.0)), had a higher probability of luteal phase deficiency (<10 days; adjusted probability ratio (PR) 1.31 (95% CI 1.00, 1.71)), had a higher probability of 2 days of premenstrual spotting (adjusted PR 2.15 (95% CI 1.09, 4.24)) and a higher probability of having two or fewer days of peak-type (estrogenic) cervical fluid (adjusted PR 1.49 (95% CI 1.03, 2.15)).

LIMITATIONS REASONS FOR CAUTION

Our study participants were geographically dispersed but relatively homogeneous in regard to race, ethnicity, income and educational levels, and all had male partners, which may limit the generalizability of the findings. We cannot exclude the possibility of undetected subfertility or related gynecologic disorders among some of the women, such as undetected endometriosis or polycystic ovary syndrome, which would impact the generalizability of our findings. Acute illness or stressful events might have reduced the likelihood of any intercourse during a cycle, while also altering cycle characteristics. Some cycles in the no intercourse group may have actually had undocumented intercourse or other sexual activity, but this would bias our results toward the null. The Creighton Model FertilityCare System (CrM) discourages use of barrier methods, so we believe that most instances of intercourse involved exposure to semen; however, condoms may have been used in some cycles. Our dataset lacks any information about the occurrence of female orgasm, precluding our ability to evaluate the independent or combined impact of female orgasm on cycle characteristics.

WIDER IMPLICATIONS OF THE FINDINGS

Sexual activity may change reproductive hormonal patterns, and/or levels of reproductive hormones may influence the likelihood of sexual activity. Future work may help with understanding the extent to which exposure to seminal fluid, and/or female orgasm and/or timing of intercourse could impact menstrual cycle function. In theory, large data sets from women using menstrual and fertility tracking apps could be informative if women can be appropriately incentivized to record intercourse completely. It is also of interest to understand how cycle characteristics may differ in women with gynecological problems or subfertility.

STUDY FUNDING/COMPETING INTERESTS

Funding for the research on the three cohorts analyzed in this study was provided by the Robert Wood Johnson Foundation #029258 (Creighton Model MultiCenter Fecundability Study), the Eunice Kennedy Shriver National Institute of Child Health and Human Development 1K23 HD0147901-01A1 (Time to Pregnancy in Normal Fertility) and the Office of Family Planning, Office of Population Affairs, Health and Human Services 1FPRPA006035 (Creighton Model Effectiveness, Intentions, and Behaviors Assessment). The authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Cervical mucus patterns and the fertile window in women without known subfertility: a pooled analysis of three cohorts

STUDY QUESTION

What is the normal range of cervical mucus patterns and number of days with high or moderate day-specific probability of pregnancy (if intercourse occurs on a specific day) based on cervical mucus secretion, in women without known subfertility, and how are these patterns related to parity and age?

SUMMARY ANSWER

The mean days of peak type (estrogenic) mucus per cycle was 6.4, the mean number of potentially fertile days was 12.1; parous versus nulliparous, and younger nulliparous (<30 years) versus older nulliparous women had more days of peak type mucus, and more potentially fertile days in each cycle.

WHAT IS KNOWN ALREADY

The rise in estrogen prior to ovulation supports the secretion of increasing quantity and estrogenic quality of cervical mucus, and the subsequent rise in progesterone after ovulation causes an abrupt decrease in mucus secretion. Cervical mucus secretion on each day correlates highly with the probability of pregnancy if intercourse occurs on that day, and overall cervical mucus quality for the cycle correlates with cycle fecundability. No prior studies have described parity and age jointly in relation to cervical mucus patterns.

STUDY DESIGN, SIZE, DURATION

This study is a secondary data analysis, combining data from three cohorts of women: 'Creighton Model MultiCenter Fecundability Study' (CMFS: retrospective cohort, 1990-1996), 'Time to Pregnancy in Normal Fertility' (TTP: randomized trial, 2003-2006), and 'Creighton Model Effectiveness, Intentions, and Behaviors Assessment' (CEIBA: prospective cohort, 2009-2013). We evaluated cervical mucus patterns and estimated fertile window in 2488 ovulatory cycles of 528 women, followed for up to 1 year.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were US or Canadian women age 18-40 years, not pregnant, and without any known subfertility. Women were trained to use a standardized protocol (the Creighton Model) for daily vulvar observation, description, and recording of cervical mucus. The mucus peak day (the last day of estrogenic quality mucus) was used as the estimated day of ovulation. We conducted dichotomous stratified analyses for cervical mucus patterns by age, parity, race, recent oral contraceptive use (within 60 days), partial breast feeding, alcohol, and smoking. Focusing on the clinical characteristics most correlated to cervical mucus patterns, linear mixed models were used to assess continuous cervical mucus parameters and generalized linear models using Poisson regression with robust variance were used to assess dichotomous outcomes, stratifying by women's parity and age, while adjusting for recent oral contraceptive use and breast feeding.

MAIN RESULTS AND THE ROLE OF CHANCE

The majority of women were <30 years of age (75.4%) (median 27; IQR 24-29), non-Hispanic white (88.1%), with high socioeconomic indicators, and nulliparous (70.8%). The mean (SD) days of estrogenic (peak type) mucus per cycle (a conservative indicator of the fertile window) was 6.4 (4.2) days (median 6; IQR 4-8). The mean (SD) number of any potentially fertile days (a broader clinical indicator of the fertile window) was 12.1 (5.4) days (median 11; IQR 9-14). Taking into account recent oral contraceptive use and breastfeeding, nulliparous women age ≥30 years compared to nulliparous women age <30 years had fewer mean days of peak type mucus per cycle (5.3 versus 6.4 days, P = 0.02), and fewer potentially fertile days (11.8 versus 13.9 days, P < 0.01). Compared to nulliparous women age <30 years, the likelihood of cycles with peak type mucus ≤2 days, potentially fertile days ≤9, and cervical mucus cycle score (for estrogenic quality of mucus) ≤5.0 were significantly higher among nulliparous women age ≥30 years, 1.90 (95% confidence interval (CI) 1.18, 3.06); 1.46 (95% CI 1.12, 1.91); and 1.45 (95% CI 1.03, 2.05), respectively. Between parous women, there was little difference in mucus parameters by age. Thresholds set a priori for within-woman variability of cervical mucus parameters by cycle were examined as follows: most minus fewest days of peak type mucus >3 days (exceeded by 72% of women), most minus fewest days of non-peak type mucus >4 days (exceeded by 54% of women), greatest minus least cervical mucus cycle score >4.0 (exceeded by 73% of women), and most minus fewest potentially fertile days >8 days (found in 50% of women). Race did not have any association with cervical mucus parameters. Recent oral contraceptive use was associated with reduced cervical mucus cycle score and partial breast feeding was associated with a higher number of days of mucus (both peak type and non-peak type), consistent with prior research. Among the women for whom data were available (CEIBA and TTP), alcohol and tobacco use had minimal impact on cervical mucus parameters.

LIMITATIONS, REASONS FOR CAUTION

We did not have data on some factors that may impact ovulation, hormone levels, and mucus secretion, such as physical activity and body mass index. We cannot exclude the possibility that some women had unknown subfertility or undiagnosed gynecologic disorders. Only 27 women were age 35 or older. Our study participants were geographically dispersed but relatively homogeneous with regard to race, ethnicity, income, and educational level, which may limit the generalizability of the findings.

WIDER IMPLICATIONS OF THE FINDINGS

Patterns of cervical mucus secretion observed by women are an indicator of fecundity and the fertile window that are consistent with the known associations of age and parity with fecundity. The number of potentially fertile days (12 days) is likely greater than commonly assumed, while the number of days of highly estrogenic mucus (and higher probability of pregnancy) correlates with prior identifications of the fertile window (6 days). There may be substantial variability in fecundability between cycles for the same woman. Future work can use cervical mucus secretion as an indicator of fecundity and should investigate the distribution of similar cycle parameters in women with various reproductive or gynecologic pathologies.

STUDY FUNDING/COMPETING INTEREST(S)

Funding for the three cohorts analyzed was provided by the Robert Wood Johnson Foundation (CMFS), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (TTP), and the Office of Family Planning, Office of Population Affairs, Health and Human Services (CEIBA). The authors declare that they have no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Menstrual bleeding, cycle length, and follicular and luteal phase lengths in women without known subfertility: A pooled analysis of three cohorts

BACKGROUND

There is variability between women for days of menstrual bleeding, cycle lengths, follicular phase lengths, and luteal phase lengths, related to age and parity.

OBJECTIVE

To describe total cycle length; anovulatory cycles; follicular and luteal phase lengths; and days and intensity of menstrual and non-menstrual bleeding in women without known subfertility over the course of 1 year.

METHODS

581 women (3,324 cycles) with no known subfertility (18-40 years of age) were followed for up to 1 year. Women recorded vaginal bleeding and mucus discharge daily. We used the peak day of cervical mucus as the estimated day of ovulation and the last day of the follicular phase. We used generalised linear mixed models stratified by age and parity to describe menstrual cycle parameters.

RESULTS

The majority of women were <30 years of age (74.5%), non-Hispanic White (88.6%), and nulliparous (70.4%). The mean menses length was 6.2 (1.5) days, median 6; cycle length 30.3 (6.7) days, median 29; follicular phase length 18.5 (6.5) days, median 17; and luteal phase length 11.7 (2.8) days, median 12. Nulliparous women aged ≥30 years vs nulliparous women aged <30 had shorter cycles (29.2 days, 95% confidence interval (CI) 27.8, 30.7 vs 31.5 days, 95% CI 30.8, 32.2) and shorter follicular phases (17.6 days, 95% CI 16.2, 18.9 vs 19.6 days, 95% CI 18.9, 20.2). Among all women, within-woman differences between the longest and shortest menses length >3 days, total cycle length >7 days, follicular phase >7 days, and luteal phase >3 days were found in 11.6%, 43.0%, 41.7%, and 58.8% of women, respectively.

CONCLUSIONS

Our findings confirm variability between women of menstrual cycle parameters related to age and parity, and also highlight within-woman variability in the follicular and luteal phases.

Association between diminished ovarian reserve and luteal phase deficiency

OBJECTIVE

To determine the association between biomarkers of ovarian reserve and luteal phase deficiency (LPD).

DESIGN

Secondary analysis of a prospective time-to-conceive cohort study.

SETTING

Not applicable.

PATIENT(S)

Women attempting conception, aged 30-44 years, without known infertility.

INTERVENTION(S)

Measurement of early follicular phase serum levels of antimüllerian hormone, FSH, inhibin B, and E₂.

MAIN OUTCOME MEASURE(S)

The primary outcome was LPD, defined by luteal bleeding (LB) (≥1 day of LB) or a short luteal phase length (≤11 days).

RESULT(S)

Overall, 755 women provided information on 2,171 menstrual cycles and serum for measurement of at least one biomarker of ovarian reserve. There were 2,096 cycles from 754 women in the LB cohort, of which 40% experienced LB. After adjusting for age, race, previous miscarriages, and previous pregnancies, diminished ovarian reserve (DOR) was not significantly associated with LB. Low early follicular phase FSH levels increased the odds of LB (odds ratio [OR] 1.84; 95% confidence interval [CI] 1.25-2.71), as did high early follicular phase E₂ levels (OR 1.59; 95% CI 1.26-2.01). A total of 608 cycles from 286 women were included in the analysis of luteal phase length, of which 13% had a short luteal phase. After adjusting for age, there was no significant association between DOR and a short luteal phase. The risk of a short luteal phase decreased with increasing inhibin B (OR 0.61; 95% CI 0.45-0.81).

CONCLUSION(S)

Although DOR is not associated with LPD, hormone dysfunction in the early follicular phase may contribute to LPD in women of older reproductive age.

Development and validation of a pain monitoring app for patients with musculoskeletal conditions (The Keele pain recorder feasibility study)

Background

Assessing daily change in pain and related symptoms help in diagnosis, prognosis, and monitoring response to treatment. However, such changes are infrequently assessed, and usually reviewed weeks or months after the start of treatment. We therefore developed a smartphone application (Keele Pain Recorder) to record information on the severity and impact of pain on daily life. Specifically, the study goal was to assess face, content and construct validity of data collection using the Pain Recorder in primary care patients receiving new analgesic prescriptions for musculoskeletal pain, as well as to assess its acceptability and clinical utility.

Methods

The app was developed with Keele’s Research User Group (RUG), a clinical advisory group (CAG) and software developer for use on Android devices. The app recorded pain levels, interference, sleep disturbance, analgesic use, mood and side effects. In a feasibility study, patients aged > 18 attending their general practitioner (GP) with a painful musculoskeletal condition were recruited to use the app twice per day for 28 days. Face and construct validity were assessed through baseline and post-study questionnaires (Spearman’s rank correlation coefficient). Usability and acceptability were determined through post-study questionnaires, and patient, GP, RUG and CAG interviews.

Results

An app was developed which was liked by both patients and GPs. It was felt that it offered the opportunity for GPs to discuss pain control with their patients in a new way. All participants found the app easy to use (it did not interfere with their activities) and results easy to interpret. Strong associations existed between the first 3 days (Spearman r = 0.79) and last 3 days (r = 0.60) of pain levels and intensity scores on the app with the validated questionnaires.

Conclusions

Collaborating with patient representatives and clinical stakeholders, we developed an app which can be used to help clinicians and patients monitor painful musculoskeletal conditions in response to analgesic prescribing. Recordings were accurate and valid, especially, for pain intensity ratings, and it was easy to use. Future work needs to examine how pain trajectories can help manage changes in a patient’s condition, ultimately assisting in self-management.

Electronic supplementary material

The online version of this article (10.1186/s12911-019-0741-z) contains supplementary material, which is available to authorized users.

Prediction of pregnancy after frozen-thawed embryo transfer via in vivo intrauterine oxidation-reduction potential measurements: a pilot study

PURPOSE

During the implantation period, the uterus goes through many complex, orchestrated changes, including alterations of the glycocalyx that are due to sialylation, sulfation, and fucosylation. A previous mouse study showed that the in vivo intrauterine oxidation-reduction potential (ORP) aided in determining the alterations in the uterine endometrium that are suitable for implantation and for evaluating prospective uterine receptivity, while the in vivo intrauterine pH did not. It was assessed if the in vivo intrauterine ORP could be a useful parameter to predict pregnancy in women.

METHODS

A prospective cohort study was conducted for patients who had received a frozen-thawed single embryo transfer in a programmed, hormonally controlled cycle. The in vivo intrauterine ORP was measured 3 times during the treatment cycle, at cycle days 9-10, 1 day before progesterone administration and immediately before the embryo transfer.

RESULTS

The amount of in vivo intrauterine ORP at 9-10 days after the start of menstrual bleeding was significantly lower in the pregnant group than in the non-pregnant group. A receiver-operator characteristic curve analysis of the intrauterine ORP as a predictor of non-conception showed an area under the curve of 0.80.

CONCLUSION

The in vivo intrauterine ORP could be a useful parameter to predict pregnancy for the frozen-thawed embryo transfer treatment cycle.

Prospective evaluation of the impact of intermenstrual bleeding on natural fertility

OBJECTIVE

To evaluate the impact of an episode of intermenstrual bleeding on the probability of conception in a menstrual cycle (fecundability).

DESIGN

Prospective, time-to-pregnancy cohort study.

SETTING

Community-based cohort.

PATIENT(S)

Women trying to conceive, ages 30 to 44 years, without known infertility.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Current cycle and subsequent cycle fecundability.

RESULT(S)

A total of 549 women provided 1,552 complete cycles for analysis. Intermenstrual and luteal bleeding were reported in 36% and 34% of cycles, respectively. Ninety-three percent of all intermenstrual bleeding was luteal. Cycles in which women had intermenstrual bleeding or luteal bleeding were statistically significantly less likely to result in conception (fecundability ratio [FR] 0.23; 95% confidence interval [CI], 0.16-0.34; and FR 0.22; 95% CI, 0.14-0.33). Women with an episode of intermenstrual and luteal bleeding had a statistically significant increase in the probability of pregnancy in the subsequent cycle (FR 1.61; 95% CI, 1.15-2.25; and FR 2.01; 95% CI, 1.52-2.87, respectively).

CONCLUSION(S)

Intermenstrual bleeding statistically significantly decreases the odds of conceiving in that cycle but does not appear to negatively impact a woman's immediate future reproductive potential.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01028365.

Three-dimensional Doppler sonography in asymptomatic and symptomatic women after medical termination of pregnancy

OBJECTIVES

To characterize the 3D Doppler sonographic appearance of the uterine cavity in asymptomatic and symptomatic women after administration of mifepristone and misoprostol for medical termination of pregnancy.

METHODS

A prospective observational study was performed. Women admitted for medical termination of pregnancy underwent transvaginal sonography 15 days after the procedure. Volumes were acquired, and offline analyses of the 3D vascularization indices were performed. Outcomes were collected at the follow-up scan and by telephone after the termination. Women were subclassified as asymptomatic or symptomatic according to the presence/absence of fever, vaginal bleeding, abdominal/pelvic pain, and infections. Spotting was defined as any episodic vaginal bleeding that was less than an expected menstruation and not regarded as a symptom.

RESULTS

A total of 104 women who underwent medical termination of pregnancy between 6 and 9 weeks' gestation were enrolled in the study. The termination procedure was successful in 98% of cases; among them, 9 women (8.6%) were symptomatic due to bleeding. Two asymptomatic women required surgery; 1 had sonographic evidence of suspected retained products of conception (endometrial thickness ≥ 15 mm or power Doppler vascularization presence). Fifty-seven women (55%) presented with retained products of conception. All the women with suspected retained products regained normal menses; of these, 3 symptomatic women with retained products (2.9%) underwent a 1-month sonographic follow-up. The symptomatic status was not associated with endometrial thickness, 3D intrauterine mass volume, or 2-dimensional (2D) and 3D power Doppler appearances.

CONCLUSIONS

The necessity of surgery after medical termination of pregnancy cannot be predicted by sonography. In cases with sonographic evidence of suspected retained products of conception, endometrial thickness, 2D Doppler findings, and the 3D vascularization indices correlated poorly with bleeding symptoms. Long-term follow-up should be considered in symptomatic women, and it can avoid any unnecessary surgical intervention.

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.

Persistent organochlorine pollutants and menstrual cycle characteristics

An evolving body of evidence suggests an adverse relation between persistent organochlorine pollutants (POPs) and menstruation, though prospective longitudinal measurement of menses is limited and served as the impetus for study. We prospectively assessed the relation between a mixture of persistent organochlorine compounds and menstrual cycle length and duration of bleeding in a cohort of women attempting to become pregnant. Eighty-three (83%) women contributing 447 cycles for analysis provided a blood specimen for the quantification of 76 polychlorinated biphenyls and seven organochlorine pesticides, and completed daily diaries on menstruation until a human chorionic gonadotropin confirmed pregnancy or 12 menstrual cycles without conception. Gas chromatography with electron capture detection was used to quantify concentrations (ng g(-1)serum); enzymatic methods were used to quantify serum lipids (mg dL(-1)). A linear regression model with a mixture distribution was used to identify chemicals grouped by purported biologic activity that significantly affected menstrual cycle length and duration of bleeding adjusting for age at menarche and enrollment, body mass index, and cigarette smoking. A significant 3-d increase in cycle length was observed for women in the highest tertile of estrogenic PCB congeners relative to the lowest tertile (β=3.20; 95% CI 0.36, 6.04). A significant reduction in bleeding (<1 d) was observed among women in the highest versus lowest tertile of aromatic fungicide exposure (γ=-0.15; 95% CI -0.29, -0.00). Select POPs were associated with changes in menstruation underscoring the importance of assessing chemical mixtures for female fecundity.

Working conditions associated with ovarian cycle in a medical center nurses: a Taiwan study

AIM

Decreased basal body temperature measurements predict ovulation with an accuracy of 74%. The anovulatory cycle exhibits an ovarian monophasic pattern. This study evaluated the relationship between ovarian cycle pattern and sociodemographic characteristics, menstrual history and work characteristics of nurses in a Taiwan medical center.

METHODS

Of 200 nurses recruited, 151 were analyzed. Each subject completed questionnaires and provided life recordings and daily basal body temperature measurements during the 14-week study.

RESULTS

The analytical results demonstrated that work place (P = 0.014) and work shift (P = 0.048) are significantly related to ovarian cycle pattern. Nurses who worked in emergent care units and wards had a higher prevalence of irregular ovarian cycle pattern. Approximately 53% of nurses who worked rotating shifts exhibited irregular ovarian cycle pattern.

CONCLUSIONS

Nurses who either had rotating shift work or worked in emergent care units and wards should be concerned with their own ovarian cycle pattern for their health.