It is now well accepted that a woman can conceive from an act of intercourse for a maximum of only about 7 days of her menstrual cycle. The reliability of natural family planning depends on identifying this window of fertility without ambiguity. Several symptomatic markers, cervical mucus and basal body temperature, have been used extensively and with considerable success in most women but failures occur. Ovarian and pituitary hormone production show characteristic patterns during the cycle. Urinary estrogen and pregnanediol measurements yield reliable information concerning the beginning, peak, and end of the fertile period, provided that the assays are accurate and performed on timed specimens of urine. We have developed such enzyme immunoassays for urinary estrogen and pregnanediol glucuronides that can be performed at home. In the early versions of the assays, enzyme reaction rates were measured by eye, but more recently, a simple photoelectronic rate meter has been used. The final problem to be solved is not technologic but whether women are sufficiently motivated to expend the same time and effort each day for 10 days a month, with less cost, on fertility awareness as they spend on making a cup of tea.
natural family planning urinary hormone monitoring, Brown JB urinary estrogen pregnanediol fertility awareness, enzyme immunoassay home fertility testing estrogen glucuronide, Billings method cervical mucus hormone confirmation, fertile window identification urinary hormone assay, pregnanediol glucuronide home monitoring ovulation, natural family planning reliability hormone measurement, basal body temperature cervical mucus hormone correlation, ovarian hormone patterns menstrual cycle fertility, urinary estrogen assay fertile period identification, home-based hormone monitoring natural family planning, pituitary ovarian hormone cycle fertility awareness method
PMID 3314524 3314524 DOI 10.1016/s0002-9378(87)80137-0 10.1016/s0002-9378(87)80137-0 Brown et al. 1987, Brown 1987
Cite this article
Brown, J. B., Blackwell, L. F., Billings, J. J., Conway, B., Cox, R. I., Garrett, G., Holmes, J., & Smith, M. A. (1987). Natural family planning. American journal of obstetrics and gynecology, 157(4 Pt 2), 1082-1089. https://doi.org/10.1016/s0002-9378(87)80137-0
Brown JB, Blackwell LF, Billings JJ, Conway B, Cox RI, Garrett G, et al. Natural family planning. Am J Obstet Gynecol. 1987;157(4 Pt 2):1082-1089. doi:10.1016/s0002-9378(87)80137-0
Brown, J. B., et al. "Natural family planning." American journal of obstetrics and gynecology, vol. 157, no. 4 Pt 2, 1987, pp. 1082-1089.
What are the characteristics of, and how variable are, individual normal menstrual cycle profiles of excretion rates for the urinary metabolites oestrone glucuronide (E1G) and pregnanediol glucuronide (PdG)? There is a continuum of menstrual cycle profiles that differ from standard textbook profiles but which can be understood simply in terms of growth, atresia and ovulation of ovarian follicles. Point-of-care assays with the Ovarian Monitor pre-coated assay tubes, using urine samples diluted to a constant volume per unit time, give laboratory accurate clinical data for individual menstrual cycles. Lay operators can perform the point-of-care assay system at home to achieve reliable and reproducible results, which can be used for natural family planning. STUDY DESIGN, SIZE, This prospective study involved 62 women, with normal menstrual cycles, recruited from three centres: Palmerston North, New Zealand, Sydney, Australia and Santiago, Chile. The study lasted 3 years. PARTICIPANTS/MATERIALS, SETTING, Women collected daily urine samples and determined their E1G and PdG rates with a pre-coated enzyme assay system known as the Ovarian Monitor. For two cycles, the assays were repeated in a study centre and the results were averaged to give 113 individual menstrual cycles for analysis. The cycles were displayed individually in a proprietary database program. MAIN The individual normal hormonal profiles were more complex than the classic composite curves for 40% of the cycles. Of 113 ostensibly normal cycles, only 91 were potentially fertile and 22 had some luteal phase defect. The oestrone glucuronide and PdG excretion rates were reliable and informative in the non-invasive elucidation of ovulation and ovarian function for both simple and complex profiles. Daily monitoring revealed the variability of normal menstrual cycle profiles. The LH peaks were variable and ambiguous markers for ovulation. LIMITATIONS, The study consisted of cycles only from women with regular cycles of 20-40 days duration. All the women were intending to avoid a pregnancy during the study thus the limits of the fertile window were not tested. The principles established in this study should apply to cycles of any length. All peaks in oestrone glucuronide excretion should be tested by concurrent measurements of PdG, which gives a positive indication of the fate of the follicle it represents. The Ovarian Monitor provides a useful addition for practitioners of natural family planning. STUDY FUNDING/COMPETING INTEREST(S): Financial support for this study was obtained from the UNDP/UNFPA/World Bank/WHO Special Programme of Research, Development and Research Training in Human Reproduction (HRP). D.G.C. is currently employed by and holds stock in Manawatu Diagnostics Ltd, a company in the development phase of a potentially competing product. The remaining authors have nothing to declare.
Cycle Across the Lifespan · Cycle and General Health
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.