Current Medical Research: Summer/Fall 2017

Modeling fertile window differences across the reproductive lifespan with quantitative urine hormone monitoring of the menstrual cycle

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.

Variations in ovulation time and menstrual cycle characteristics: analysis of a prospective long-term cohort study

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.

Hormone Changes in Polycystic Ovarian Syndrome Identified with a Personal Quantitative Urine Monitor: A Pilot Study

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.

The State of the Science of Natural Family Planning: A Report from NFP Scientists' Meeting Held in Orlando, FL, September 4, 2024

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.

Current Medical Research: Winter/Spring 2017

Fehring RJ et al., 2018 · Linacre Q · Free full text on PubMed Central

Multisite Effectiveness Study of the Marquette Method of Natural Family Planning Program

Mu Q et al., 2022 · Linacre Q · Free full text on PubMed Central

Women of reproductive age need reliable and effective family planning methods to manage their fertility. Natural family planning (NFP) methods or fertility awareness-based methods (FABMs) have been increasingly used by women due to their health benefits. Nevertheless, effectiveness of these natural methods remains inconsistent, and these methods are difficult for healthcare providers to implement in their clinical practice. The purpose of this study is to evaluate the effectiveness of the Marquette Model NFP system to avoid pregnancy for women at multiple teaching sites using twelve months of retrospectively collected teaching data. Survival analysis (Kaplan-Meier) was used to determine typical unintended pregnancy rates for a total of 1,221 women. There were forty-two unintended pregnancies which provided a typical use unintended pregnancy rate of 6.7 per 100 women over twelve months of use. Eleven of the forty-two unintended pregnancies were associated with correct use of the method. The total unintended pregnancy rate over twelve months of use was 2.8 per 100 for women with regular cycles, 8.0 per 100 women for the postpartum and breastfeeding women, and 4.3 per 100 for women with irregular menstrual cycles. The Marquette Model system of NFP was effective when provided by health professionals who completed the Marquette Model NFP teacher training program. This study involved determining whether healthcare professionals at ten sites across the United States and Canada trained to provide the Marquette Method NFP services can replicate the effectiveness demonstrated in previous studies of the method. We found a high level of effectiveness (i.e., very low pregnancy rates) in using the Marquette Method among women from various regions across North America with diverse reproductive backgrounds and in particular when using hormonal fertility marker. Healthcare providers who have been trained to teach NFP can successfully incorporate NFP services in their practice and assist their clients in choosing appropriate family planning methods.

The State of the Science of Natural Family Planning Fifty Years after Humane Vitae: A Report from NFP Scientists' Meeting Held at the US Conference of Catholic Bishops, April 4, 2018

Manhart MD et al., 2018 · Linacre Q · Free full text on PubMed Central

A one-day meeting of physicians, professional nurses, and scientists actively involved in Natural Family Planning (NFP) research was held to review the state of the science of NFP and consider future priorities. The meeting had four (i) determine the gaps in research evidence for secure methods of NFP among women of all reproductive categories, (ii) determine the gaps in the research and development of new technology for providing NFP services, (iii) determine the gaps in the research that determine the benefits and challenges with use of NFP among married couples, and (iv) provide prioritized ideas for future research needs from the analysis of evidence gaps from objectives above. This article summarizes the discussion and conclusions drawn from topics reviewed. While much has been accomplished in the fifty years since Humane vitae, there are still many gaps to address. Five areas for future research in NFP were identified as high priority: (1) well-designed method effectiveness studies among various reproductive categories including important subpopulations (postpartum, perimenopause, posthormonal contraceptive), normally cycling women (especially US women), and comparative studies between NFP methods; (2) validation studies to establish the benefit of charting fertility signs (both currently known and potential new indicators) as a screening tool for women's health issues; (3) ongoing independent evaluation of fertility monitoring apps to provide users perspective on the relative merits of each and to identify those most worthy of further effectiveness testing; (4) studies evaluating the impact of new technologies on NFP adoption, use, and persistence; and (5) creation of a shared database across various NFP methods to collaborate on shared research interests, longitudinal studies, and so on. This summarizes a meeting to review the scientific and medical progress related to natural family planning made in the 50 years since Humane Vitae and to define priorities for future work. Areas reviewed included the evidence for avoiding pregnancy in normally cycling, postpartum, and perimenopausal women, the impact of new technology, including fertility charting apps, on NFP, and the impact on relationships and personal well-being from use of NFP. Five priority focus areas for future research were also identified.

Effectiveness of an Online Natural Family Planning Program for Breastfeeding Women

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.