Bouchard TP et al., 2026·Journal of ovarian research·
Open Access
Reproductive hormones of the fertile window are often referenced to women in regular cycles, but this may not be representative of the hormonal profiles of women in different circumstances like polycystic ovarian syndrome, the postpartum period, and the perimenopause transition. This observational cohort study sought to identify the variability in the reproductive hormones in various clinical circumstances and to establish potential thresholds for each category based on hormone measurements with the Mira urinary hormone monitor. A total of 57 women (ages 22-51) in various circumstances (regular cycles, polycystic ovarian syndrome, postpartum and perimenopause) tracked Mira urine hormone measurements (estrone-3-glucuronide, luteinizing hormone, pregnanediol glucuronide), contributing 444 cycles of data. Using additive mixed models, hormone values were stratified by the four different reproductive categories. The perimenopause and polycystic ovarian syndrome groups demonstrated relative hypoestrogenic states, while the perimenopause group showed low luteal pregnanediol glucuronide and the polycystic ovarian syndrome/polyendocrine metabolic ovarian syndrome (PCOS/PMOS) group showed high luteal pregnanediol glucuronide. The perimenopause group had significantly higher luteinizing hormone values throughout the whole cycle. The fertile window hormone thresholds vary depending on a woman's specific reproductive category. Women in different circumstances should not necessarily use the same hormonal thresholds for the fertile window and ovulation. A larger dataset with ultrasound correlation to ovulation is required to delineate the fertile window with more precision. Hormone differences across the menstrual cycle could be used for targeted treatments in polycystic ovarian syndrome and perimenopause women.
Bouchard TP et al., 2025·Preprints.org·
Open Access
Background/Objectives: Quantitative urine monitors are increasingly being used for a personalized approach to improve menstrual cycle knowledge and to manage fertility. Although several studies have evaluated urine fertility monitors in regular cycles, there is limited research in the use of quantitative monitors in reproductive disorders, such as polycystic ovarian syndrome (PCOS). Urine hormone data was collected with the Mira monitor from 20 participants, 10 of whom had PCOS and a matched group who had regular cycles. The main aim of this study was to evaluate the levels of luteinizing hormone (LH), estrone-3-glucuronide (E13G), and pregnanediol glucuronide (PDG) in PCOS menstrual cycles compared to regular cycles. Women with PCOS had higher BMI than regular cycling women (p=0.02). PCOS cycles were longer (p<0.05), peak day was later in the menstrual cycle (p<0.001), and luteal length was shorter (p < 0.01) compared to regular cycles. In whole cycle comparisons, E13G was found to be lower in PCOS cycles (p<0.01) and PDG was found to be higher in PCOS cycles (p<0.05). E13G was also lower in the follicular phase of and late luteal phase of PCOS cycles (p<0.00001). The results of this study demonstrate the feasibility of detecting hormonal differences in PCOS compared to regular cycles with at-home measurements with the Mira monitor. The metabolic dysregulation of PCOS is a possible factor in these hormone changes. Larger studies with different sub-types of PCOS will be needed to further clarify these changes and to understand the pathophysiology behind these hormonal changes.
Cycle Across the Lifespan · Cycle and General Health
Background Reproductive hormones of the fertile window are often referenced to women in regular cycles, but this may not be representative of the hormonal profiles of women in different circumstances like polycystic ovarian syndrome, the postpartum period, and the perimenopause transition. This observational cohort study sought to identify the variability in the hormones of the fertile window in various reproductive categories and to establish potential thresholds for each category based on hormone measurements with the Mira urinary hormone monitor. Results A total of 57 women (ages 22–51) in various circumstances (regular cycles, polycystic ovarian syndrome, postpartum and perimenopause) tracked Mira urine hormone measurements (estrone-3-glucuronide, luteinizing hormone, pregnanediol glucuronide), contributing 444 cycles of data. Using additive mixed models, hormone values were stratified by the four different reproductive categories. The perimenopause and polycystic ovararian syndrome groups demonstrated relative hypoestrogenic states, while the perimenopause group showed low luteal pregnanediol glucuronide and the polycystic ovarian syndrome group showed high luteal pregnanediol glucuronide. The perimenopause group had higher luteinizing hormone values throughout the whole cycle. Conclusion The fertile window hormone thresholds vary depending on a woman’s specific reproductive category. Women in different circumstances should not necessarily use the same hormonal thresholds for the fertile window and ovulation. A larger dataset with ultrasound correlation to ovulation is required to delineate the fertile window with more precision. Hormone differences across the menstrual cycle could be used for targeted treatments in polycystic ovarian syndrome and perimenopause women.
Measurement and Statistics · Instrument Development and Validation
Bouchard TP et al., 2025·Womens Health Rep (New Rochelle)·
Open Access
Measuring quantitative menstrual cycle hormones at home may help women better understand their postpartum and perimenopause fertility transitions, but these quantitative fertility monitors require validation. This study included 16 North American women, aged 28-51, during either the postpartum (n = 8, cycles = 18) or perimenopause (n = 8, cycles = 35) fertility transitions testing daily first-morning urine testing with both the Mira Monitor and ClearBlue Fertility Monitor (CBFM) along with menstrual cycle parameter tracking. The main outcome measures were a rise in estrone-3-glucuronide (E13G) and luteinizing hormone (LH) urine hormone values from the Mira monitor correlated to low, high, or peak values on the CBFM. Both in the postpartum and perimenopause transitions, the identification of the day of ovulation based on the LH surge on the Mira and CBFM monitors was highly correlated (R = 0.94 and 0.83, p < 0.001). The E13G levels on the Mira monitor were significantly higher for a CBFM reading of "High" compared with "Low" for both the postpartum and perimenopausal cycles (all p < 0.001). Similarly, the LH levels on the Mira monitor were significantly higher for a CBFM reading of "Peak" (LH surge) compared with "High" for both the postpartum and perimenopausal cycles (all p < 0.001). The LH surge and levels of E13G in urine identified on the quantitative Mira fertility monitor strongly correlate to the LH surge and the shift from low to high on the CBFM during the postpartum and perimenopause transitions.
The ovarian cycle has a well-established circa-monthly rhythm, but the mechanisms involved in its regularity are unknown. Is the rhythmicity driven by an endogenous clock-like timer or by other internal or external processes? Here, using two large epidemiological datasets (26,912 cycles from 2303 European women and 4786 cycles from 721 North American women), analyzed with time series and circular statistics, we find evidence that the rhythmic characteristics of the menstrual cycle are more likely to be explained by an endogenous clock-like driving mechanism than by any other internal or external process. We also show that the menstrual cycle is weakly but significantly influenced by the 29.5-day lunar cycle and that the phase alignment between the two cycles differs between the European and the North American populations. Given the need to find efficient treatments of subfertility in women, our results should be confirmed in larger populations, and chronobiological approaches to optimize the ovulatory cycle should be evaluated.
Meyers M et al., 2023·Medicina (Kaunas)·
Open Access
The fertility tracking of menstrual cycles during perimenopause with a quantitative hormone monitor is a novel undertaking. Women in regular menstrual cycles have been tracking their fertility using different biomarkers since the 1960's. Presently, there are newer electronic hormonal devices used to track fertility that provide more exact and objective data to help delineate the fertile time frame of a woman's cycle. These devices measure quantitative levels of estrogen, the luteinizing hormone, progesterone, and follicle-stimulating hormone, all of which occur at varying levels during the menstrual cycle. As women advance toward menopause, their cycles vary in length, and their hormones fluctuate. In this retrospective analysis, forty-two women aged 40 to 50 tracked their cycles over time, and eight of these forty-two women used the quantitative hormonal device. With the use of this device, the perimenopausal period has revealed distinct hormonal cycle characteristics that are unique to this group of women. It is the purpose of this paper to discuss these cycle's characteristics during perimenopause, which were found with the use of the quantitative hormonal device.
The uses of cervical mucus and basal body temperature as indicators of return to fertility postpartum have resulted in high unintended pregnancy rates. In 2013, a study found that when women used urine hormone signs in a postpartum/breastfeeding protocol this resulted in fewer pregnancies. To improve the original protocol's effectiveness, three revisions were made: (1) women were to increase the number of days tested with the Clearblue Fertility Monitor, (2) an optional second luteinizing hormone test could be done in the evening, and (3) instructions were given to manage the beginning of the fertile window for the first six cycles postpartum. The purpose of this study was to determine the correct and typical use effectiveness rates to avoid pregnancy in women who used a revised postpartum/breastfeeding protocol. A cohort review of an established data set from 207 postpartum breastfeeding women who used the protocol to avoid pregnancy was completed using Kaplan-Meier survival analysis. Total pregnancy rates that included correct and incorrect use pregnancies were eighteen per one hundred women over twelve cycles of use. For the pregnancies that met a priori criteria, the correct use pregnancy rates were two per one hundred over twelve months and twelve cycles of use and typical use rates were four per one hundred women at twelve cycles of use. The protocol had fewer unplanned pregnancies than the original, however, the cost of the method increased.
Bouchard TP et al., 2022·J Womens Health (Larchmt)·
Some studies have suggested minor changes in the menstrual cycle after COVID-19 vaccination, but more detailed analyses of the menstrual cycle are needed to evaluate more specific changes in the menstrual cycle that are not affected by survey-based recall bias. Using a pretest-post-test quasi-experimental evaluation of menstrual cycle parameters before and after COVID-19 vaccination, we conducted an anonymous online survey of two groups of North American women who prospectively monitor their menstrual cycle parameters daily including bleeding patterns, urinary hormone levels using the ClearBlue Fertility Monitor, or cervical mucus observations. The primary outcome measures were cycle length, length of menses, menstrual volume, estimated day of ovulation (EDO), luteal phase length, and signs of ovulation. Perceived (subjective) menstrual cycle changes and stressors were also evaluated in this study as secondary outcome measures. Of the 279 women who initiated the survey, 76 met the inclusion criteria and provided 588 cycles for analysis (227 pre-vaccine cycles, 145 vaccine cycles, 216 post-vaccine cycles). Although 22% of women subjectively identified changes in their menstrual cycle, there were no significant differences in menstrual cycle parameters (cycle length, length of menses, EOD, and luteal phase length) between the pre-vaccine, vaccine, and post-vaccine cycles. COVID-19 vaccines were not associated with significant changes in menstrual cycle parameters. Perceived changes by an individual woman must be compared with statistical changes to avoid confirmation bias.
Bouchard TP et al., 2019·Front Public Health·
Open Access
Progesterone rises \~24-36 h after ovulation. Past studies using ultrasound-confirmed ovulation have shown that three consecutive tests with a threshold of 5μg/mL of urine progesterone (pregnanediol-3-glucuronide, PDG), taken after the luteinizing hormone (LH) surge, confirmed ovulation with 100% specificity. The purpose of this study was to a evaluate a new urine PDG self-test to retrospectively confirm ovulation in women who were monitoring ovulation using a hormonal fertility monitor. Thirteen women of reproductive age were recruited to test urine PDG while using their home hormonal fertility monitor. The monitor measured the rise in estrogen (estrone-3-glucuronide, E3G) and LH to estimate the fertile phase of the menstrual cycle. The women used an online menstrual cycle charting system to track E3G, LH and PDG levels for four menstrual cycles. The participants (Mean age 33.6) produced 34 menstrual cycles of data (Mean length 28.4 days), 17 of which used a PDG test with a threshold of 7μg/mL and 17 with a threshold of 5μg/mL. In the cycles that used the 7μg/mL test strips, 59% had a positive confirmation of ovulation, and with the 5μg/mL test strips, 82% of them had a positive confirmation of ovulation. The 5μg/mL PDG test confirmed ovulation in 82% of cycles and could assist women in the evaluation of the luteal progesterone rise of their menstrual cycle.
Bouchard TP et al., 2018·Front Med (Lausanne)·
Open Access
To determine the effectiveness of achieving pregnancy with focused intercourse in the fertile window identified using natural fertility indicators. 24-cycle prospective effectiveness study.
A North American web-based fertility monitoring service. 256 North American women aged 20-43 (mean age 29.2 years) seeking to achieve pregnancy. Participants identified their fertile window with either electronic hormonal fertility monitoring or cervical mucus monitoring, or both, and recorded their observations on an online fertility tracking system. Pregnancies were validated by nurses with an online self-assessed pregnancy evaluation form. Survival analysis was used to determine pregnancy rates. There were 150 pregnancies among the 256 participants with an overall pregnancy rate of 78 per 100 women over 12 menstrual cycles. There were 54 pregnancies (68%) among the 80 women using the fertility monitor, 11 pregnancies (46%) among the 24 women using mucus monitoring, and 90 (63%) among the 143 women using both mucus and monitor. The 12-cycle pregnancy rates per 100 women were 83 (monitor group), 72 (mucus group), and 75 (mucus and monitor group). Pregnancy rates reached 100% at 24 cycles of use for those women using the hormonal fertility monitor. Use of the hormonal fertility monitor alone seems to offer the best natural estimate of the fertile phase of the menstrual cycle for women wishing to achieve a pregnancy. Focusing intercourse through 24 menstrual cycles can be beneficial for achieving pregnancy.
Fehring RJ et al., 2017·J Obstet Gynecol Neonatal Nurs·
To analyze the effectiveness of an online, nurse-managed natural family planning (NFP) program among breastfeeding women and subgroups of these women.
Longitudinal comparative cohort study.
A university-based online NFP education program and menstrual cycle charting system. Women (N = 816) with a mean age of 30.3 years (standard deviation = 4.5) who registered to use the online NFP system and indicated they were breastfeeding. Participants tracked their fertile times with an electronic hormone fertility monitor (EHFM), cervical mucus monitoring, or both. All unintended pregnancies were evaluated by professional nurses. The correct use pregnancy rates were 3 per 100 users over 12 cycles of use, and typical rates were 14 per 100 at 12 cycles of use. At 12 cycles of use, total pregnancy rates were 16 per 100 for electronic hormone fertility monitor users (n = 380), 81 per 100 among mucus-only users (n = 45), and 14 per 100 for electronic hormone fertility monitor plus mucus users (n = 391). Use of a nurse-managed online NFP program for women can be effective to help women avoid pregnancy while breastfeeding, especially with correct and consistent use.
Fehring RJ et al., 2016·MCN Am J Matern Child Nurs·
The aims of this study were to determine and compare extended use-effectiveness of an online nurse-managed fertility education service program among women (and subgroups of women) seeking to avoid pregnancy. This was a 24-month prospective study of a university-based online Web site with 663 nonbreastfeeding women using an online charting system to avoid pregnancy. Participants tracked their fertility online with either cervical mucus monitoring, electronic hormonal fertility monitoring, or both fertility indicators. Unintended pregnancies were validated by professional nurses. Participants had a mean age of 30.4 years (SD = 6.3) and mean 1.7 children (SD = 2.0). Among the 663 nonbreastfeeding participants there were 2 unintended pregnancies per 100 at 24 cycles of correct use and 15 pregnancies at 24 cycles of typical use. However, the 212 women using the electronic fertility monitor had a typical use unintended pregnancy rate of 6 at 24 cycles of use in comparison with the 118 women using cervical mucus monitoring that had a typical use pregnancy rate of 19 at 24 cycles and with the 333 women using both fertility indicators that had a pregnancy rate of 18 at 24 cycles of use. CLINICAL Use of the fertility monitor to estimate fertility among nonbreastfeeding women provides the most secure method of avoiding pregnancy.
Fehring RJ et al., 2015·J Midwifery Womens Health·
The length of periodic abstinence, due to overestimation of the fertile phase of the menstrual cycle, is often a cause for dissatisfaction, discontinuation, and user error with natural family planning (NFP) methods. The objective of this research was to compare the length of required abstinence (ie, estimated fertility) and coital frequency between 2 NFP methods. This was an analysis of data from a 12-month prospective comparison study in which participants were randomized into either an electronic hormonal fertility monitor (EHFM) group or a cervical mucus monitoring (CMM) group-both of which included a fertility algorithm as a double check for the beginning and end of the estimated fertile window. The number of days of estimated fertility and coitus was extracted from each menstrual cycle of data, and t tests were used to compare the means of these 2 variables between the 2 NFP methods. The study involved 197 women (mean [SD] age 29.7 [5.4]) who used the EHFM to estimate the fertile window and 160 women (mean [SD] age 30.4 [5.3]) who used CMM to estimate the fertile window. They produced 1,669 menstrual cycles of data. After 12 months of use, the EHFM group had statistically fewer days of estimated fertility than the CMM group (mean [SD] days, 13.25 [2.79] vs 13.68 [2.99], respectively; t = 2.07; P = .039) and significantly more coitus (mean [SD] coital acts, 4.22 [3.16] vs 4.05 [2.88], respectively; t = 1.17; P = .026). The use of the EHFM seems to provide more objectivity and confidence in self-estimating the fertile window and using nonfertile days for intercourse when avoiding pregnancy.
Fehring RJ et al., 2013·MCN Am J Matern Child Nurs·
To determine the influence of mutual motivation on unintended pregnancy rates of couples who used natural family planning (NFP) methods to avoid pregnancy. Using an online taught NFP method, 358 women and (their male partners) indicated "how much" and "how hard" they wished to avoid pregnancy on a scale of 0 to 10 before each menstrual cycle charted over 12 month of use. This motivation scale is used in the National Survey of Family Growth as a measure of motivation. All pregnancies were verified with an online pregnancy evaluation and urine-based pregnancy test. A combined motivation score was used in analysis. There were 28 pregnancies among the low-motivation participants (N = 60) and 16 among the high-motivation participants (N = 298). At 12 months of use, there were 75 pregnancies per 100 users for the low-motivation group and only 8 for the high-motivation group. There was an 80% greater likelihood of a pregnancy with the low-motivation group (χ = 25.5, p < .001, odds ratio = 1.80; 95% confidence interval = 1.61-1.90).
Clinical High motivation to avoid pregnancy by both the female user of a behavioral method of family planning and her male partner is required for high efficacy. Assessing motivation of both the woman and her male partner before prescribing NFP methods is recommended.
The postpartum period is a challenging time for family planning, especially for women who breastfeed. Breastfeeding delays the return of menses (lactational amenorrhea), but ovulation often occurs before first menses. For this reason, a protocol was developed to assist women in identifying their return of fertility postpartum to avoid pregnancy. In this prospective, 12-month, longitudinal cohort study, 198 postpartum women aged 20 to 45 years (mean age, 30.2 years) were taught a protocol for avoiding pregnancy with either online or in-person instruction. A hand-held fertility monitor was used to identify the fertile period by testing for urinary changes in estrogen and luteinizing hormone, and the results were tracked on a web site. During lactational amenorrhea, urine testing was done in 20-day intervals. When menses returned, the monitor was reset at the onset of each new menstrual cycle. Participants were instructed to avoid intercourse during the identified fertile period. Kaplan-Meier survival analysis was used to calculate unintentional pregnancy rates through the first 12 months postpartum. There were 8 unintended pregnancies per 100 women at 12 months postpartum. With correct use, there were 2 unintended pregnancies per 100 women at 12 months. The online postpartum protocol may effectively assist a select group of women in avoiding pregnancy during the transition to regular menstrual cycles.
Fehring RJ et al., 2012·Contraception·
Open Access
The aim was to compare the efficacy and acceptability of two Internet-supported fertility-awareness-based methods of family planning. Six hundred and sixty-seven women and their male partners were randomized into either an electronic hormonal fertility monitor (EHFM) group or a cervical mucus monitoring (CMM) group. Both groups utilized a Web site with instructions, charts and support. Acceptability was assessed online at 1, 3 and 6 months. Pregnancy rates were determined by survival analysis. The EHFM participants (N=197) had a total pregnancy rate of 7 per 100 users over 12 months of use compared with 18.5 for the CMM group (N=164). The log rank survival test showed a significant difference (p<.01) in survival functions. Mean acceptability for both groups increased significantly over time (p<.0001). Continuation rates at 12 months were 40.6% for the monitor group and 36.6% for the mucus group. In comparison with the CMM, the EHFM method of family planning was more effective. All users had an increase in acceptability over time. Results are tempered by the high dropout rate.
The Standard Days Method (SDM) is a method of family planning that assumes ovulation to be close to the midpoint of the menstrual cycle; fertility falls between days 8 and 19; and is most effective for cycle lengths between twenty-six and thirty-two days. The purpose of this study was to evaluate the assumptions of the SDM with a new data set of 714 menstrual cycles produced by 131 women (mean age twenty-nine) who tracked their fertility with an electronic fertility monitor that measured urinary estrogen and luteinizing hormone (LH). The LH peak was used to estimate the day of ovulation (EDO) and the six-day fertile window. Results indicated the majority (80 percent) of menstrual cycles had EDOs within three days of the midpoint of the cycle (86 percent with cycle lengths between twenty-six and thirty-two days). Approximately 22.5 percent (172) of the cycles had fertile window days outside of days 8 to 19, 10.2 percent (78) before, and 12.1 percent (92) after. However, there is a low probability of pregnancy when women experience short cycles and the early days of the fertile window are outside of days 8 through 19. We concluded assumptions of the SDM outside of the fertile window with long cycles could be problematic. However, the SDM is valid for women who have most cycles within the twenty-six to thirty-two day range.
Fehring RJ et al., 2011·J Obstet Gynecol Neonatal Nurs·
Open Access
To evaluate the efficacy, knowledge of fertility, and acceptability of a web-based natural family planning (NFP) education and service program.
A 6-month repeated measure longitudinal evaluation pilot study.
A university based online website. The website was piloted with 468 volunteer women seeking NFP services. Of these participants, 222 used the automatic online fertility charting system to avoid pregnancy. The 222 charting participants had a mean age of 29.9 years (SD=5.6), 2.2 children (SD=1.9), 37% were postpartum, and 47% had regular menstrual cycle lengths. Nurse-managed web-based NFP education and service program. Outcomes: Pregnancies were confirmed by an online self-assessed pregnancy evaluation form. A 10-item fertility quiz and 10-item acceptability survey was administered online. Among the 222 users avoiding pregnancy, at 6 months of use, there were two correct-use unintended pregnancies that provided a pregnancy rate of 2% and seven total unintended pregnancies providing a typical use pregnancy rate of 7%. Mean knowledge of fertility increased significantly from time of registration (8.96, SD=1.10) to 1 month of use (9.46, SD=.10), t=4.60, p<.001). Acceptability increased nonsignificantly from 1 month of use (45.6; SD=8.98) to 6 months of use (48.4; SD=8.77). The nurse-managed online NFP system seems to provide adequate knowledge of fertility and help participants meet pregnancy intentions. Acceptability of such a system of NFP is still in question.
Nassaralla CL et al., 2011·J Womens Health (Larchmt)·
Menstrual cycle function may continue to be altered after discontinuation of oral contraceptives (OC). Few studies have been published on the effects of recent OC use on menstrual cycle parameters; none have examined characteristics of the menstrual flow or the quality of cervical mucus. The purpose of this retrospective matched cohort study is to assess biomarkers of the menstrual cycle after discontinuation of OCs. Among a sample of women who daily recorded observations of menstrual cycle biomarkers, 70 women who had recently discontinued OCs were randomly matched by age and parity with 70 women who had not used OCs for at least 1 year. Outcomes investigated included overall cycle length, length of the luteal phase, estimated day of ovulation, duration of menstrual flow, menstrual intensity, and mucus score. Differences between recent OC users and controls were assessed using random effects modeling. Recent OC users had statistically significantly lower scores for mucus quality for cycles 1 and 2. Additionally, OC users had a later estimated day of ovulation that was statistically significant in cycle 2 and a decreased intensity of menstrual flow that was significant in the first four cycles (difference = -0.48 days). In random effects modeling, all these parameters were significantly different for the first six cycles combined. Menstrual cycle biomarkers are altered for at least two cycles after discontinuation of OCs, and this may help explain the temporary decrease in fecundity associated with recent OC use.
To determine if an electronic hormonal fertility monitor aided method (EHFM) of family planning is more effective than a cervical mucus only method (CMM) in helping couples to avoid pregnancy. Six hundred twenty-eight women were taught how to avoid pregnancy with either the EHFM (n=313) or the CMM (n = 315). Both methods involved standardized group teaching and individual follow-up. All pregnancies were reviewed and classified by health professionals. Correct use and total unintended pregnancy rates over 12 months of use were determined by survival analysis. Comparisons of unintended pregnancies between the 2 methods were made by use of the Fisher exact test. There were a total of 28 unintended pregnancies with the EFHM and 41 with the CMM. The 12-month correct use pregnancy rate of the monitor-aided method was 2.0%, and the total pregnancy rate was 12.0%. In comparison, the 12-month correct use pregnancy rate of the CMM was 3.0%, and the total pregnancy rate was 23.0%. There was a significant difference in total pregnancies between the 2 groups (p<0.05). EFHM is more effective than CMM. Further research is needed to verify the results.
Fehring RJ et al., 2008·MCN Am J Matern Child Nurs·
To determine the effectiveness of the Marquette Method (MM) of natural family planning (NFP) as a method of avoiding pregnancy. This was a 12-month retrospective evaluation of the MM system of NFP. Two hundred and four women (mean age, 28.6 years) and their male partners (mean age, 30.3 years) who sought to learn a method for avoiding pregnancy with the MM from four clinical sites were taught to track their fertility by self-observation of cervical mucus, by use of an electronic monitor that measures urinary levels of estrone-3-glucuronide and luteinizing hormone, and by use of basal body temperature. All unintended pregnancies were evaluated by professional nurses as to whether they were intended or not. Pregnancy rates over 12 months of use were determined by survival analysis. There were a total of 12 unintended pregnancies, only 1 with correct use. The 12-month "correct use" pregnancy rate was 0.6 (i.e., 99.4% effective) and the "typical use" (total pregnancy rate) was 10.6 (i.e., 89.4% effective) per 100 users.
Clinical When used correctly, the MM system of NFP is an effective means of avoiding pregnancy. The efficacy of the MM system includes proper preparation of the professional nurse NFP teachers.
The purpose of this study was to determine the variability in length of the fertile phase of the menstrual cycle with 140 participants who produced 1,060 cycles with an electronic hormonal fertility monitor. The length of the fertile phase, as defined by the first day with a threshold level of urinary E3G and ending with a second day above a threshold of LH, varied from <1 to >7 days, with the most frequent length being 3 days.
Fehring RJ et al., 2007·J Obstet Gynecol Neonatal Nurs·
Open Access
To determine the effectiveness of an electronic hormonal fertility monitor plus cervical mucus monitoring to avoid pregnancy.
A 12-month prospective clinical efficacy trial. One hundred ninety five (195) women (mean age 29.8 years) seeking to avoid pregnancy with a natural method at 5 clinical sites in 4 cities. Each participant was taught to track fertility by self-observation of cervical mucus and an electronic monitor that measures urinary levels of estrone-3-glucuronide and luteinizing hormone. Correctand typical-use unintended pregnancy rates. There were a total of 26 unintended pregnancies, 3 with correct use. With 1,795 months of use, the correct-use pregnancy rate was 2.1% per 12 months of use (i.e., 97.9% effective in avoiding pregnancy when rules of the method were always followed) and the imperfect-use pregnancy rate was 14.2% per 12 months of use (i.e., 85.8% effective in avoiding pregnancy when rules of the method were not always followed and all unintended pregnancies and months of use were included in the calculations). Correct use of an electronic hormonal fertility monitor with cervical mucus observations can be as effective as other fertility awareness-based methods of natural family planning. Comparative studies are needed to confirm this conclusion.
Fehring RJ et al., 2006·J Obstet Gynecol Neonatal Nurs·
Open Access
To determine variability in the phases of the menstrual cycle among healthy, regularly cycling women.
A prospective descriptive study of a new data set with biological markers to estimate parameters of the menstrual cycles. One hundred forty one healthy women (mean age 29 years) who monitored 3 to 13 menstrual cycles with an electronic fertility monitor and produced 1,060 usable cycles of data. Outcomes: Variability in the length of the menstrual cycle and of the follicular, fertile, and luteal phases, and menses. The estimated day of ovulation and end of the fertile phase was the peak fertility reading on the monitor (i.e., the urinary luteinizing hormone surge). Mean total length was 28.9 days (SD = 3.4) with 95% of the cycles between 22 and 36 days. Intracycle variability of greater than 7 days was observed in 42.5% of the women. Ninety-five percent of the cycles had all 6 days of fertile phase between days 4 and 23, but only 25% of participants had all days of the fertile phase between days 10 and 17. Among regularly cycling women, there is considerable normal variability in the phases of the menstrual cycle. The follicular phase contributes most to this variability.
A protocol was developed and evaluated for nonovulating breastfeeding women to determine potential fertility with an electronic hormonal fertility monitor. The amount of required abstinence (i.e., days of potential fertility) through the first menstrual cycle indicated by the fertility monitor was significantly lower (17% of the total days) compared with the amount of abstinence (50% of the total days) indicated by the self-observation of cervical mucus.
Fehring RJ et al., 2004·Contraception·
Open Access
The purpose of this study was to compare the fertile phase of the menstrual cycle as determined by the Clearplan Easy Fertility Monitor (CPEFM) with self-monitoring of cervical mucus. One-hundred women (mean age = 29.4 years) observed their cervical mucus and monitored their urine for estrogen and luteinizing hormone metabolites with the CPEFM on a daily basis for 2-6 cycles and generated 378 cycles of data; of these, 347 (92%) had a CPEFM peak. The beginning of the fertile window was, on average, day 11.8 (SD = 3.4) by the monitor and day 9.9 (SD = 3.0) by cervical mucus (r = 0.43, p < 0.001). The average first day of peak fertility by the monitor was 16.5 (SD = 3.6) and by cervical mucus 16.3 (SD = 3.7) (r = 0.85, p < 0.001). The mean length of the fertile phase by the monitor was 7.7 days (SD = 3.1) and by cervical mucus 10.9 days (SD = 3.7) (t = 12.7, p < 0.001). The peak in fertility as determined by the monitor and by self-assessment of cervical mucus is similar but the monitor tends to underestimate and self-assessment of cervical mucus tends to overestimate the actual fertile phase.