Fehring, R. J. (1990). Methods used to self-predict ovulation. A comparative study. Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, 19(3), 233-237. https://doi.org/10.1111/j.1552-6909.1990.tb01642.x
Fehring RJ. Methods used to self-predict ovulation. A comparative study. J Obstet Gynecol Neonatal Nurs. 1990;19(3):233-237. doi:10.1111/j.1552-6909.1990.tb01642.x
Fehring, R. J. "Methods used to self-predict ovulation. A comparative study." Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, vol. 19, no. 3, 1990, pp. 233-237.
Cervical mucus charting tracked the LH surge in 28 of 29 cycles
A small 1990 study of 20 regularly cycling women found that LH surges fell on or up to three days before peak mucus in 28 of 29 cycles. The 29 were the cycles with a detectable surge.
Key Findings
Twenty women aged 22 to 41 years (mean, 29.4 years) with regular cycles and no known fertility problems tracked mucus and urine LH for two cycles.
A total of 29 of the 38 cycles had detectable LH surges.
Of the 29 cycles with LH surges, 9 (31%) had the surge on the peak day, 9 (31%) the day before, 6 (20.7%) two days before, 4 (13.8%) three days before.
Twenty-eight (96.5%) of the 29 cycles with LH surges had the surge on or within three days before the peak day. One cycle (3.5%) had no peak day.
Six of the nine cycles without a detectable surge were either 25 days or shorter or 35 days long.
Interpretation
The study is a small comparison of two markers in women chosen on purpose. All 20 had been taught the Creighton Model and attended one natural family-planning clinic. Each used the urine test once a day, and 9 of 38 cycles had no detected surge. The study compared only mucus and urine LH. All but one cycle had a detectable peak day, and the paper states this does not mean every cycle was ovulatory. Women with fertility problems, irregular cycles, or hormone medication were outside the sample.
RRM Context
The Creighton Model defines the peak day as the last day of clear, stretchy, or lubricative mucus. Daily charting fits the cycle-charting-informed principle of restorative reproductive medicine. Fehring gives one example: a woman's second cycle showed an LH surge but no observable mucus, which the urine kit alone would not have shown. He adds that mucus charting gives the approximate length of the luteal phase.
Our editorial summary of this paper, not the article's abstract.
Abstract
Time of ovulation as detected by a self-test of luteinizing hormone (LH) in the urine was compared with time of ovulation as detected by self-observation of cervical mucus. Twenty regularly cycling women monitored their cervical mucus and urine LH for two complete menstrual cycles. Of the cycles that had an LH surge, 100% were on the peak day of cervical mucus or within three days before the peak day. Self-observation of cervical mucus, therefore, can be an accurate method of determining optimal fertility.
Bouchard TP et al., 2026·Journal of ovarian research·Free to read
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.
Malliou-Becher MN et al., 2026·Human reproduction (Oxford, England)
What are the variations in ovulation time and menstrual cycle characteristics among and within various individuals over the course of 12 menstrual cycles? There are considerable variations in both cycle length and ovulation time, with pronounced intra-individual variability over a 12-cycle observation period. Although it is commonly believed that healthy women have regular cycles with a predictable mid-cycle ovulation, more recent research shows a significant variation in cycle length and ovulation time. Previous studies have focused only on cycle length, often excluding cycles outside the 25-35-day range, thus limiting the understanding of natural variation; they have also lacked precise ovulation diagnostics or included small sample sizes, making it difficult to capture the full scope of cycle and ovulation variability. Similarly, a recent big data study, while valuable, was limited by a self-selected group and the absence of accurate ovulation diagnostics, reducing its generalizability. STUDY DESIGN, SIZE, This study was designed as a prospective long-term observational study, which involved collecting data from 1923 women with a total of 43 999 menstrual cycles from January 1985 to July 2019. After fulfilling the inclusion criteria, the main group consisted of 1051 women, all of whom contributed data for 12 cycles (12 612 cycles), including 420 conception cycles. PARTICIPANTS/MATERIALS, SETTING, Participants in the study were between 18 and 44 years of age at study entry and did not take any reproductive hormones. Women who were postpartum, breastfeeding, amenorrheic, or within a 3-month period after stopping hormonal contraception were excluded. Participants agreed to keep cycle records according to the symptothermal method, 'Sensiplan'. Ovulation time was determined using an evidence-based algorithm based on evaluating cervical mucus patterns and basal body temperature shifts, with ovulation time defined as the day before the temperature rise. Data analysis was descriptive, using absolute and relative frequencies, standard deviation, percentiles, and ranges. Age dependency was assessed using unpaired sample t-tests and one-way ANOVA. Linear regression was used to assess long-term trends. MAIN In 62.4% of women, cycle lengths varied by 1 week or more within 12 cycles. Accordingly, the time of ovulation varied by 1 week or more within 12 cycles in 54.8% of women, with 96.5% experiencing fluctuations of 4 days or more over the 12 months. The median spontaneous cycle length was 28 days, with a mean of 29.66 days (SD = 7.55). Only 52.7% of women consistently had cycle lengths between 23 and 35 days across all 12 cycles. Ovulation occurred most frequently between Days 12 and 16, with almost half of conceptions (45.7%) occurring after Day 16. A one-way analysis of variance revealed a significant reduction in mean cycle length with increasing age (P < 0.001), showing the shortest median cycle length of 27 days being in women aged 40-44 years. Age also impacted ovulation time, with women aged 35-39 years showing more stable ovulation patterns compared to younger women. Over the 34-year study period, average cycle length increased slightly but significantly (β = 0.0161, P = 0.0306), corresponding to approximately half a day. Intra-individual variability also showed a slight, but non-significant, upward trend (β = 0.0262, P = 0.2173). LIMITATIONS, Comorbidities such as hyperprolactinemia, obesity, and PCOS were not systematically excluded. However, by including only women with at least 12 cycles, the study largely avoided severe hormonal disorders. This study highlights the considerable individual variation of ovulation time and cycle length over 12 menstrual cycles. These findings contribute to a better understanding of fertility awareness, and highlight the implications for family planning and reproductive health management. STUDY FUNDING/COMPETING INTEREST(S): The authors declare no conflicts of interest. No funding was provided. N/A.
Bouchard TP et al., 2025·Preprints.org·Free to read
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.
Manhart MD et al., 2025·Linacre Q·Free full text on PubMed Central
A one-day meeting was held as a pre-conference to the Catholic Medical Association Annual Educational event in 2024. A panel of eighteen physicians, scientists, and researchers involved in NFP work was convened to review the available evidence in four topical areas: (i) evidence for effectiveness of NFP methods to postpone and achieve pregnancy, (ii) evidence for effectiveness in the postpartum and perimenopause transition periods, (iii) evaluate the current state of technology in NFP (specifically app and quantitative hormone monitoring), and (iv) evidence examining the impact of NFP on marital relations. In each topical area, the panel worked to reach a consensus opinion on the currently available evidence and identified priorities for further research. Results from these discussions and a set of priorities for further work are presented here.
An expert panel was convened to review the current evidence supporting use of NFP in various settings, utilization of new technology, and the impact of NFP on marital dynamics. Results from these discussions and a set of priorities for further work are presented here.
The (PD) peak day of cervical mucus is an important biologic marker for the self-determination of the optimal time of fertility in a woman's menstrual cycle. The purpose of this article is to provide evidence (literature and empiric) for the accuracy of the PD of cervical mucus as a biologic marker of peak fertility and the estimated day of ovulation. An analysis of data from four published studies that compared the self-determination of the PD of cervical mucus with the urinary luteinizing hormone (LH) surge was conducted. The four studies yielded 108 menstrual cycle charts from 53 women participants. The 108 cycles ranged in length from 22 to 75 days (mean 29.4 SD 6.0). Ninety-three of the 108 cycles had both an identified PD and LH surge. Data charts showed that 97.8% of the PD fell within +/-4 days of the estimated day of ovulation. Use of a standardized mucus cycle scoring system indicated that the peak in cervical mucus ratings was highest on the day of the LH surge. Self-determination of the PD of cervical mucus is a very accurate means of determining peak fertility and a fairly accurate means of determining the day of ovulation and the beginning of the end of the fertile time.
Past practices of Natural Family Planning (NFP) have included such techniques as: 1) calendar rhythm in which a constant mathematical relationship was calculated between the day of ovulation and the beginning of the succeeding menstrual period, 2) temperature rhythm in which sexual intercourse is permitted by observing that the basal body temperature rises at the time of ovulation, 3) a combination of calendar and temperature rhythm methods, 4) paper test strips which measure glucose and electrolytes in vaginal secretions, 5) electronic devices of various sorts which record changes in the potentials of the pelvic organs at the time of ovulation, and 6) recent developments in computer technology which measure a number of variables. All of these techniques depend upon the identification of the fertile and infertile periods of the menstrual cycle. More recent studies by the World Health Organization have analyzed the teaching phase of NFP and the effectiveness phase of NFP using the detection of ovulation by following changes in the quality of cervical mucus. These studies tested 869 women with varied backgrounds in 5 countries. The data support the fact that many motivated women can detect ovulation reasonably accurately by following changes in their cervical mucus (the Billings method), although teaching time and motivation are considerable. Long-term and detailed data are necessary to determine the value of these methods. The advantage of NFP is the avoidance of drugs and devices. Disadvantages are that demands are placed on the sex life of couples, and there are associations between failures and increased rates of congenital abnormalities.
Chang CP et al., 2020·Paediatr Perinat Epidemiol·Free full text on PubMed Central
Previous research has demonstrated that women instructed in fertility awareness methods can identify the Peak Day of cervical mucus discharge for each menstrual cycle, and the Peak Day has high agreement with other indicators of the day of ovulation. However, previous studies enrolled experienced users of fertility awareness methods or were not fully blinded. To assess the agreement between cervical mucus Peak Day identified by fertile women without prior experience on assessing cervical mucus discharge with the estimated day of ovulation (1 day after urine luteinising hormone surge). This study is a secondary analysis of data from a randomised trial of the Creighton Model FertilityCare(TM) System (CrM), conducted 2003-2006, for women trying to conceive. Women who had no prior experience tracking cervical mucus recorded vulvar observations daily using a standardised assessment of mucus characteristics for up to seven menstrual cycles. Four approaches were used to identify the Peak Day. The referent day was defined as one day after the first identified day of luteinising hormone (LH) surge in the urine, assessed blindly. The percentage of agreement between the Peak Day and the referent day of ovulation was calculated. Fifty-seven women with 187 complete cycles were included. A Peak Day was identified in 117 (63%) cycles by women, 185 (99%) cycles by experts, and 187 (100%) by computer algorithm. The woman-picked Peak Day was the same as the referent day in 25% of 117 cycles, within ±1 day in 58% of cycles, ±2 days in 84%, ±3 days in 87%, and ±4 days in 92%. The ±1 day and ± 4 days' agreement was 50% and 90% for the expert-picked and 47% and 87% for the computer-picked Peak Day, respectively. Women's daily tracking of cervical mucus is a low-cost alternative for identifying the estimated day of ovulation.
The purpose of this study was to compare the CUE Ovulation Predictor with the ovulation method in determining the fertile period. Eleven regularly ovulating women measured their salivary and vaginal electrical resistance (ER) with the CUE, observed their cervical-vaginal mucus, and measured their urine for a luteinizing hormone (LH) surge on a daily basis. Data from 21 menstrual cycles showed no statistical difference (T = 0.33, p = 0.63) between the CUE fertile period, which ranged from 5 to 10 days (mean = 6.7 days, SD = 1.6), and the fertile period of the ovulation method, which ranged from 4 to 9 days (mean = 6.5 days, SD = 2.0). The CUE has potential as an adjunctive device in the learning and use of natural family planning methods.
Rick Fehring, Dick Fehring, Rich Fehring, R Fehring
PMID 2358920 2358920 DOI 10.1111/j.1552-6909.1990.tb01642.x 10.1111/j.1552-6909.1990.tb01642.x Fehring et al. 1990, Fehring 1990
Cite this article
Fehring, R. J. (1990). Methods used to self-predict ovulation. A comparative study. Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, 19(3), 233-237. https://doi.org/10.1111/j.1552-6909.1990.tb01642.x
Fehring RJ. Methods used to self-predict ovulation. A comparative study. J Obstet Gynecol Neonatal Nurs. 1990;19(3):233-237. doi:10.1111/j.1552-6909.1990.tb01642.x
Fehring, R. J. "Methods used to self-predict ovulation. A comparative study." Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, vol. 19, no. 3, 1990, pp. 233-237.
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