Fehring, R. J. (1991). New technology in natural family planning. Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, 20(3), 199-205. https://doi.org/10.1111/j.1552-6909.1991.tb02531.x
Fehring RJ. New technology in natural family planning. J Obstet Gynecol Neonatal Nurs. 1991;20(3):199-205. doi:10.1111/j.1552-6909.1991.tb02531.x
Fehring, R. J. "New technology in natural family planning." Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, vol. 20, no. 3, 1991, pp. 199-205.
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In recent years, several new devices have been developed to help women achieve or avoid pregnancy. These devices include computerized basal body temperature thermometers, electronic fertility monitors, and chemical and hormonal ovulation detection kits. This article describes these new fertility devices and discusses their effectiveness and impact on helping women understand and control their 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.
Calendar-based methods are not usually considered effective or useful methods of family planning among health professionals. However, new "high-" and "low"-tech calendar methods have been developed, which are easy to teach, to use, and may be useful in helping couples avoid pregnancy. The low-tech models are based on a fixed-day calendar system. The high-tech models are based on monitoring urinary metabolites of female reproductive hormones. Both systems have high levels of satisfaction. This article describes these new models of family planning and the research on their effectiveness. The author proposes a new algorithm for determining the fertile phase of the menstrual cycle for either achieving or avoiding pregnancy.
Blackwell L et al., 2018·Linacre Q·Free full text on PubMed Central
Natural family planning (NFP) methods have served many generations well, and in particular, the symptothermal or symptohormonal methods. The comparison of daily mucus and temperature records for individual cycles with daily hormone measurements, which is now possible, shows that some of the assumptions underlying NFP may not be completely accurate. The various methods are inadvertently depending on an element of chance, which, of course, cannot be known by the NFP user. However, it is statistically inevitable that such errors will result eventually in an unexpected pregnancy, and these discrepancies are the likely reason for the method failures. Further research and integration of home hormone measurements with NFP symptoms are needed.
Traditional NFP methods, based on the observations of temperature, mucus, and luteinizing hormone, can work well. However, these data are sometimes difficult to interpret, and significant changes in the variables are sometimes "missing" from some cycles. Changes in these variables are elicited by the estrogen and progesterone released from the ovaries. It follows that the direct measures of events in the ovaries are the levels of estrogen and progesterone or their derivatives in blood or urine. Measurements of urinary derivatives of estrogen and progesterone can be used to monitor the ovaries directly and are clearer indicators than traditional NFP methods.
Four points on the basal body temperatures (BBT) curve have been correlated with the estimated time of ovulation (ETO), as determined by indirect hormonal parameters, in 74 menstrual cycles from 24 subjects. Only 10 of 66 hormonally
Reliable indicators to detect the fertile and infertile phases in the menstrual cycle are now available, largely due to the intensive scientific research into fertility over the past decade. This means that couples who follow the rules of the different NFP methodologies have a highly effective means of birth control, without the introduction of hormones, chemicals or devices into the body. New scientific techniques can be expected within the next couple of years which will simplify the detection of the fertile phase and hopefully help to elucidate the grey area of the early fertile days, where most of the unplanned pregnancies occur. Fertility awareness by both partners is an important positive contribution to the whole sexual relationship and emphasizes that NFP is an educational delivery system rather than a technological one. The modification of sexual behaviour and the motivation of both partners for the successful use of NFP may initially present a problem to some couples. On the other hand, many partners find the discipline enhances their sexual relationship and dialogue. Whatever the motivation, today more and more couples are happier to be in autonomous control of their bodies and their fertility.
Fertility Awareness › Technology › Home Hormone Tests
Richard J Fehring
Rick Fehring, Dick Fehring, Rich Fehring, R Fehring
PMID 2056356 2056356 DOI 10.1111/j.1552-6909.1991.tb02531.x 10.1111/j.1552-6909.1991.tb02531.x Fehring et al. 1991, Fehring 1991
Cite this article
Fehring, R. J. (1991). New technology in natural family planning. Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, 20(3), 199-205. https://doi.org/10.1111/j.1552-6909.1991.tb02531.x
Fehring RJ. New technology in natural family planning. J Obstet Gynecol Neonatal Nurs. 1991;20(3):199-205. doi:10.1111/j.1552-6909.1991.tb02531.x
Fehring, R. J. "New technology in natural family planning." Journal of obstetric, gynecologic, and neonatal nursing : JOGNN, vol. 20, no. 3, 1991, pp. 199-205.
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