Evaluating Pregnancy Rates in Fertility Awareness-Based Methods for Family Planning: Simulated Comparison of Correct Use to Avoid, Method-Related, and Total Pregnancy Rates.

Fertility awareness-based methods (FABMs), also known as natural family planning (NFP), enable couples to identify the days of the menstrual cycle when intercourse may result in pregnancy ("fertile days"), and to avoid intercourse on fertile days if they wish to avoid pregnancy. Thus, these methods are fully dependent on user behavior for effectiveness to avoid pregnancy. For couples and clinicians considering the use of an FABM, one important metric to consider is the highest expected effectiveness (lowest possible pregnancy rate) during the correct use of the method to avoid pregnancy. To assess this, most studies of FABMs have reported a method-related pregnancy rate (a cumulative proportion), which is calculated based on all cycles (or months) in the study. In contrast, the correct use to avoid pregnancy rate (also a cumulative proportion) has the denominator of cycles with the correct use of the FABM to avoid pregnancy. The relationship between these measures has not been evaluated quantitatively. We conducted a series of simulations demonstrating that the method-related pregnancy rate is artificially decreased in direct proportion to the proportion of cycles with intermediate use (any use other than correct use to avoid or targeted use to conceive), which also increases the total pregnancy rate. Thus, as the total pregnancy rate rises (related to intermediate use), the method-related pregnancy rate falls artificially while the correct use pregnancy rate remains constant. For practical application, we propose the core elements needed to assess correct use cycles in FABM studies. Summary: Fertility awareness-based methods (FABMs) can be used by couples to avoid pregnancy, by avoiding intercourse on fertile days. Users want to know what the highest effectiveness (lowest pregnancy rate) would be if they use an FABM correctly and consistently to avoid pregnancy. In this simulation study, we compare two different measures: (1) the method-related pregnancy rate; and (2) the correct use pregnancy rate. We show that the method-related pregnancy rate is biased too low if some users in the study are not using the method consistently to avoid pregnancy, while the correct use pregnancy rate obtains an accurate estimate. Short Summary: In FABM studies, the method-related pregnancy rate is biased too low, but the correct use pregnancy rate is unbiased.

Case Reports from Women Using a Quantitative Hormone Monitor to Track the Perimenopause Transition.

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.

Effectiveness of a Postpartum Breastfeeding Protocol for Avoiding Pregnancy.

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.

A comprehensive overview by region of condoms, natural family planning, and spermicide as a contraceptive method among men aged 13-54 years attending contraceptive services in England.

OBJECTIVES: This study aimed to (1) provide a comprehensive overview of contraceptive methods self-reported by men in England, over 5 years, focusing on condoms in comparison to any male method; and (2) explore condom as a contraceptive method by region and ethnicity. STUDY DESIGN: Data were from the Sexual and Reproductive Health Services (Contraception) England census data set from 2014/15 to 2018/19. Once missing data were removed, this left a total of 365,292 men. Two binomial logistic regression models were performed. Model 1 examined ethnicity, region, and time on condom as a method of contraception; and Model 2 examined ethnicity, region, and time by any male contraceptive. Descriptive statistics were run for natural family planning and spermicide. RESULTS: Model 1 revealed a significant model, χ2 (15) = 30,976, P < 0.001, and predicted that condoms as a method decreased in London with a greater decrease in Midlands. London saw the lowest rate of decline among the non-White ethnic group, whereas North and South regions increased probability over time. The North started at a higher probability and the South at the lowest. Model 2 also revealed a significant model, χ2 (15) = 32,472, P < 0.001, with a similar pattern to Model 1. Contingency tables showed natural family planning and spermicide were the least reported methods and decreased over time. CONCLUSIONS: As any male contraceptive method appears to be decreasing in both models, reproductive health promotion is required. This study has implications for commissioning funds and for identifying regional areas of further investigation.

Understanding the perspective of women who use the Billings Ovulation Method®: a focus group study.

BACKGROUND: The Billings Ovulation Method®(the Billings Method) is a fertility awareness-based method (FABM) of family planning that relies on the observation of patterns of fertility and infertility based on vulvar sensations and appearance of discharges. This allows people to choose when to have intercourse, depending on whether they want to avoid or achieve pregnancy. Few studies have documented user experiences with FABMs. METHODS: We conducted four virtual focus groups (FGs) in May and June 2021 with current adult women users of the Billings Method. We asked questions about users' reasons for selecting a FABM and the Billings Method, positive experiences and challenges learning and using the Billings Method, and suggestions for improving the user experience. We performed a content analysis of the transcribed FGs to explore key themes from the discussions. COREQ guidelines were followed. RESULTS: Twenty women between the ages of 23 and 43 participated in the FGs. Reasons women described choosing a FABM included to follow religious beliefs, to avoid side effects of hormonal contraception, and/or to learn more about their bodies. Reasons for selecting the Billings Method included perceiving it as more precise and easier to understand than other FABMs, having a scientific basis, and being recommended by family and friends. Experiences related to learning and using the Billings Method were mainly positive. They included finding the method easy to use and learn, successfully using it to either postpone or achieve a pregnancy and increasing their awareness of their bodies. Challenges for participants included the inherent learning curve for identifying sensations at the vulva and the required periods of abstinence. Participants provided suggestions and recommendations for improving users' experience, including raising awareness of the Billings Method among healthcare providers. CONCLUSIONS: Users of the Billings Method expressed an overall positive experience when learning and using it for family planning and body awareness. Some challenges were identified that offer opportunities to improve how the Billings Method is taught and delivered. These findings can also enhance healthcare providers' interactions with FABM users, including those of the Billings Method.

Perimenopause and the Use of Fertility Tracking: 3 Case Studies.

Perimenopause is a time in a woman's life where fertility may vary depending upon her age and her reproductive stage and has been defined as the transition period prior to menopause that is characterized by irregular menses, hormonal changes, vasomotor symptoms, and declining fertility (Casper, 2020). Fertility tracking during this time in a woman's reproductive stage has not been widely studied. Employing the use of Luteinizing Hormone Urine Assay sticks, an electronic hormonal monitor device or mucus, we propose a set of guidelines to determine the potentially fertile times of a woman's cycle based on staging according to the Stages of Reproductive Aging Workshop (STRAW) criteria and illustrate their application with three case reports.

Perception and use of reversible contraceptive methods in Germany: A social listening analysis.

BACKGROUND: With an increasing array of contraceptives in the market, it is important to understand how users perceive them and how their interests evolve over time. OBJECTIVES: In this analysis, we aimed to examine the contraceptive interests of women and couples in Germany using data derived from social media posts. STUDY DESIGN: Social listening analysis. METHODS: Posts from Urbia-a German Internet community-mentioning at least one reversible contraceptive method between April 2006 and April 2021 were carefully selected by searching for a defined set of keywords and phrases. The frequency of mention of each method was studied and their trend over the last 5 years was analyzed. The significance of trends was evaluated using Mann-Kendall test. Additionally, 656 random posts were individually assessed for method transitions and problems associated with specific contraceptives. RESULTS: The contraceptive pill was the most frequently mentioned method of contraception followed by natural family planning methods, condom, hormonal coil, and copper/gold coil. Although general interest in hormonal contraception was higher compared to non-hormonal, interest in the pill decreased and interest in natural family planning and copper/gold coil increased. Most women switched from the pill to non-hormonal methods, almost half of them using a condom. Almost all migrations to natural family planning were from the pill and most migrations to non-hormonal intrauterine devices such as the coil were from hormonal methods. The common problem associated with most contraceptives was side effects. CONCLUSION: Social media provides valuable information about contraceptive experiences that can be used to monitor contraceptive prevalence patterns and attitudes within a large population in a very short span of time. A good understanding of how various contraceptives are currently perceived helps in identifying strategies for improving existing family planning policies. PLAIN LANGUAGE SUMMARY: Currently, there are a variety of contraceptive products available in the market. To understand how users perceive them and how their interest evolves over time, we analyzed social media posts from Urbia, a German Internet platform. We scraped posts between 2016 and 2021 from the "child-desire" and "contraception" forums and analyzed the relative frequency of mentions of different contraceptive methods. We also looked at 1000 individual posts from 1000 different users, analyzed method switches and the problems associated with individual methods of use. The oral pill was the most frequently mentioned method of contraception followed by natural family planning methods, condom, hormonal coil, and copper/gold coil. Over the last 5 years however, the mention of the pill dropped, whereas the mentions of natural family planning and copper or gold coil increased. Further analysis of individual posts showed most women migrating from the pill to other non-hormonal methods such as natural family planning and condom. Almost all migrations to natural family planning were from the pill and most migrations to non-hormonal intrauterine devices such as the coil were from hormonal methods. The most common problem associated with the pill and non-hormonal intrauterine devices was side effects. Through this analysis we show that social media serves as a useful tool to monitor contraceptive prevalence and attitudes within a large population in a very short span of time. Our findings give policy makers an idea on the topics where more counseling and education may be required to help women and couples find their best suited method of contraception.

Natural Family Planning, An Option in Reproductive Healthcare: A Qualitative Study on Clinicians' Perceptions.

Natural family planning (NFP) empowers women to control their reproductive health and approach fertility as a normal biological process. Although substantive literature supports their comparative effectiveness with contraceptive methods, there is a paucity of this knowledge amongst clinicians and users. This study aimed to understand clinicians' perceptions regarding offering NFP to patients as part of reproductive health care. It explored clinicians' knowledge of NFP, described their perceptions of their effectiveness, and identified enabling and deterring factors to their use. Basic Interpretive qualitative research design was appropriate in obtaining an in-depth description of this phenomenon. It was conducted in 2018 in two hospitals and clinics in Ekurhuleni health district, located East of Gauteng Province, South Africa. Fifteen doctors and nurses from diverse cultural and educational backgrounds were purposefully selected and interviewed. Transcribed data were analyzed, coded, and recurrent themes identified. Training that empowers clinicians on NFP methods and their effectiveness will improve their willingness to advocate for it and promote patient autonomy by providing comprehensive counseling on family planning methods. Further, a pro-NFP policy would drive training in undergraduate and postgraduate programs and increase public awareness, including early education of male and female children.

Effectiveness of fertility awareness-based methods for pregnancy prevention during the postpartum period.

OBJECTIVES: To summarize the evidence on typical and perfect-use effectiveness of fertility awareness-based methods for avoiding pregnancy during the postpartum period, whether breastfeeding or not. STUDY DESIGN: We conducted a systematic review of studies published in English, Spanish, French, or German by November 2021 in MEDLINE, EMBASE, CINAHL, Web of Science, and ClinicalTrials.gov. Abstract and full text reviews were completed by 2 independent reviewers. Study inclusion: at least 50 subjects who enrolled prior to experiencing 3 cycles after childbirth and were using a specific fertility awareness-based method to avoid pregnancy; unintended pregnancy rate or probability calculated; postpartum amenorrheic and postpartum cycling individuals analyzed separately; and prospectively measured pregnancy intentions and outcomes. Outcomes were abstracted and study quality was systematically assessed by 2 independent investigators. RESULTS: Four studies provided effectiveness data for 1 specific fertility awareness-based method among postpartum individuals. Of these, there were zero high quality, 1 moderate quality, and 3 low quality for our question of interest. Typical-use pregnancy probability for the first 6 cycles postpartum for Marquette Method users was 12.0 per 100 women years (standard error [SE] not reported) and for Billings Ovulation Method users ranged from 9.1 (SE 3.9) for non-lactating women <30 years old to 26.8 (SE 4.6) for lactating women <30 years old. Typical-use pregnancy probabilities for the first 6 months post-first menses for the Postpartum Bridge to Standard Days Method users was 11.8 (95% confidence interval 6.01-17.16) and for Billings Ovulation Method users was 8.5 per 100 women (SE 1.7). CONCLUSION: The current evidence on the effectiveness of each fertility awareness-based method for postpartum persons is very limited and of mostly low quality. More high quality studies on the effectiveness of fertility awareness-based method in postpartum persons are needed to inform clinical counseling and patient-centered decision-making. IMPLICATIONS: Although postpartum individuals may desire to use fertility awareness-based methods to avoid pregnancy, the evidence of the effectiveness of fertility awareness-based methods in this population is limited. More high-quality studies are needed to inform shared decision-making.

Fertility Awareness-Based Methods for Women's Health and Family Planning.

Background: Fertility awareness-based methods (FABMs) educate about reproductive health and enable tracking and interpretation of physical signs, such as cervical fluid secretions and basal body temperature, which reflect the hormonal changes women experience on a cyclical basis during the years of ovarian activity. Some methods measure relevant hormone levels directly. Most FABMs allow women to identify ovulation and track this "vital sign" of the menstrual or female reproductive cycle, through daily observations recorded on cycle charts (paper or electronic). Applications: Physicians can use the information from FABM charts to guide the diagnosis and management of medical conditions and to support or restore healthy function of the reproductive and endocrine systems, using a restorative reproductive medical (RRM) approach. FABMs can also be used by couples to achieve or avoid pregnancy and may be most effective when taught by a trained instructor. Challenges: Information about individual FABMs is rarely provided in medical education. Outdated information is widespread both in training programs and in the public sphere. Obtaining accurate information about FABMs is further complicated by the numerous period tracking or fertility apps available, because very few of these apps have evidence to support their effectiveness for identifying the fertile window, for achieving or preventing pregnancy. Conclusions: This article provides an overview of different types of FABMs with a published evidence base, apps and resources for learning and using FABMs, the role FABMs can play in medical evaluation and management, and the effectiveness of FABMs for family planning, both to achieve or to avoid pregnancy.

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

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. Summary: 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.

Trend natural family planning - an online survey to assess attitudes towards NFP among German-speaking women.

PURPOSE: To study trends regarding the use of contraceptive methods and digital health modalities and to identify target groups of natural family planning (NFP). MATERIAL AND METHODS: Using an online questionnaire specifically developed for this study in German (utilizing the online tool at 'www.surveymonkey.com'), we analysed the attitude towards NFP -methods and -apps, the need for contraceptive effectiveness in general, the perceived contraceptive effectiveness of NFP methods, and differences between NFP users and non-NFP users among 779 sexually active German-speaking women of fertile age (18-50 years) from November 2019 to October 2020. RESULTS AND CONCLUSIONS: Participants used NFP more frequently than they did five years ago. Women aged 30 years and older, with higher levels of education, who are living with a partner and have children, seem to be the target group for NFP methods. Concerning the wish for contraceptive effectiveness we found significant (p < .001) differences between NFP and non-NFP users. Furthermore, an increasing number of women wants to use NFP-methods and -apps for contraception; thus, non-hormonal contraceptive options should be offered. The majority of current NFP users stated that the handling and effectiveness of NFP have been improved by digitalisation.

Algorithms with Area under the Curve for Daily Urinary Estrone-3-Glucuronide and Pregnanediol-3-Glucuronide to Signal the Transition to the Luteal Phase.

Background and Objectives: Home fertility assessment methods (FAMs) for natural family planning (NFP) have technically evolved with the objective metrics of urinary luteinizing hormone (LH), estrone-3-glucuronide (E3G) and pregnanediol-3-glucuronide (PDG). Practical and reliable algorithms for timing the phase of cycle based upon E3G and PDG levels are mostly unpublished and still lacking. Materials and Methods: A novel formulation to signal the transition to the luteal phase was discovered, tested, and developed with a data set of daily E3G and PDG levels from 25 women, 78 cycles, indexed to putative ovulation (day after the urinary LH surge), Day 0. The algorithm is based upon a daily relative progressive change in the ratio, E3G-AUC/PDG-AUC, where E3G-AUC and PDG-AUC are the area under the curve for E3G and PDG, respectively. To improve accuracy the algorithm incorporated a three-fold cycle-specific increase of PDG. Results: An extended negative change in E3G-AUC/PDG-AUC of at least nine consecutive days provided a strong signal for timing the luteal phase. The algorithm correctly identified the luteal transition interval in 78/78 cycles and predicted the start day of the safe period as: Day + 2 in 10/78 cycles, Day + 3 in 21/78 cycles, Day + 4 in 28/78 cycles, Day + 5 in 15/78 cycles, and Day + 6 in 4/78 cycles. The mean number of safe luteal days with this algorithm was 10.3 ± 1.3 (SD). Conclusions: An algorithm based upon the ratio of the area under the curve for daily E3G and PDG levels along with a relative PDG increase offers another approach to time the phase of cycle. This may have applications for NFP/FAMs and clinical evaluation of ovarian function.

(Not) talking about fertility: the role of digital technologies and health services in helping plan pregnancy. A qualitative study.

AIM: To explore how women and their partners navigate (pre)conception healthcare and the role of Natural Cycles fertility awareness technology in this process. METHODS: In-depth interviews with 24 cisgender women aged 24-43 years who had used Natural Cycles' 'Plan a Pregnancy' mode, and six partners of Natural Cycles users, all cisgender men aged 30-39 years. Participants were recruited via direct messaging in the Natural Cycles app, social media and, for partners, snowball sampling. Purposive sampling was conducted to ensure diversity among participants. Interviews were audio-recorded and transcribed verbatim. An iterative, inductive approach was adopted for thematic data analysis. RESULTS: Natural Cycles helped most users better understand their menstrual cycles and fertility. Fertility awareness and preconception counselling with healthcare providers were uncommon. Women felt discussions about planning pregnancy in healthcare settings were often fraught with difficulties. They described not wanting to be an extra burden to overworked staff, being concerned that their worries about trying for pregnancy would be dismissed, or feeling staff did not have expertise in fertility awareness. Some women had shared their Natural Cycles data with healthcare professionals to demonstrate their menstrual cycle data or time of conception. However, it was not always clear to those not accessing services when they should seek further advice, for example, those using the app for longer time periods who had not yet conceived. CONCLUSIONS: Digital technologies can provide information and support for those wanting to conceive. They should, however, complement care in statutory services, and be accompanied by greater investment in fertility awareness and preconception support.

Fertility tracking tool for visually impaired and non-visually impaired women: A qualitative study.

Background: A natural family planning device, Fertility Tracking Tool (FTT), was developed to serve as a visual and tactile guide in monitoring the fertile and infertile days of the menstrual cycle. However, there is lack of preferences about the tool among visually impaired and non-visually impaired women. Therefore, understanding their viewpoints will provide additional input for the final design of the product. Objective: This study aimed to explore the opinions of potential users of FTT in terms of acceptability, price sensitivity, buying intention, product placement, branding, and packaging. Methods: The study employed a qualitative research design with data gathered from focus group discussions. Eleven FGD sessions were conducted participated by one group of visually impaired and ten groups of non-visually impaired women from Iligan City, Philippines, selected through purposive sampling technique. Semi-structured FGD guide was utilized, and the sessions were audio-recorded. The data were analyzed through thematic analysis. Results: The themes that emerged in the study were "adaptable" with three sub-themes (easy to use, safe to use, and aesthetic), "cost-effective", "marketable", "accessibility convenience", "remarkable brand", and "complementary packaging". The study shows that the FTT is acceptable to both visually impaired and non-visually impaired women because it is user-friendly, has no side effects, and has a unique design. The accounts implying less price sensitivity, buying intention, accessibility preferences, notable branding, and auxiliary packaging are indications of the business potential of FTT. Conclusion: This study made a novel contribution to the nursing practice as the FTT is a newly invented device for natural family planning. The strong support from the government is necessary for FTT commercialization or even free distribution to the qualified users, not only in the research locale but extending the nationwide. The extensive FTT use may increase the natural contraceptive utilization in the Philippines, resulting in improved women's health and population control. The FTT utilization can also be adapted across the globe to result in a better impact.

Quantitative versus qualitative estrogen and luteinizing hormone testing for personal fertility monitoring.

BACKGROUND: A new fertility monitor is now available that provides quantitative measurement of urinary hormones, but clinical use requires validation against an established fertility monitor that provides only qualitative results. RESEARCH DESIGN AND METHODS: Two fertility monitors were compared using daily first morning urine samples over 3 cycles of use in 21 women users with experience using a fertility monitor with the Marquette Method of Natural Family Planning. RESULTS: Women were aged 33.4 ± 5.5 years and had menstrual cycles ranging between 23 and 41 days. The quantitative Mira Monitor estimates of ovulation were highly correlated with the qualitative ClearBlue Fertility Monitor (CBFM) estimates of ovulation. Both monitors provided an accurate estimate of the fertile window. CONCLUSIONS: In this preliminary trial, the Mira monitor was shown to be effective at delineating the fertile window and ovulation. We demonstrated the feasibility of applying the Marquette Method algorithm with the use of the Mira monitor. Satisfaction differences between the two monitors did not reach statistical significance. We anticipate that quantitative fertility monitoring will give couples and health-care providers new and unprecedented insights into the menstrual cycle and fertility.

Método de Ovulação Billings: entre eficácia e desconhecimento / Billings Ovulation Method: between efficacy and lack of knowledge / Método de Ovulación Billings: entre la eficacia y el desconocimiento

Resumo Apesar dos grandes investimentos, os métodos artificiais de planejamento familiar ainda apresentam limitações. Desde a década de 1950, cientistas trabalham para desenvolver um método natural confiável. Este artigo revisa a literatura sobre o Método de Ovulação Billings, apontando sua lógica, sua eficácia, seus benefícios, seus desafios e suas regras. Trata-se de método natural, embasado em mais de cinquenta anos de pesquisas. Sua chave de leitura é o muco cervical, confiável indicador da fertilidade, e sua eficácia está entre 97% e 99%, comparável aos métodos mais eficazes. O método também é indicado para todo tipo de ciclo, pois não se baseia em cálculos, e sim na observação do muco. Conclui-se que no Brasil é preciso fortalecer programas que ofereçam educação sexual mais global à população, capacitando ainda profissionais da saúde a respeito dos métodos naturais de planejamento familiar.

Abstract Despite large investments, artificial family planning methods still have limitations. Since the 1950s, scientists have worked to develop a reliable natural method. This article reviews the literature on the Billings Ovulation Method, pointing out its logic, efficacy, benefits, challenges, and rules. It is a natural method, based on more than fifty years of research. Its reading key is the cervical mucus, a reliable indicator of fertility, and its efficacy is between 97 and 99%, comparable to most effective methods. Billings is also suitable for all types of cycles, as it is not based on calculations, but on the observation of the mucus. In conclusion, Brazil needs to strengthen programs that offer more global sexual education to the population, also training health professionals on natural family planning methods.

Resumen A pesar de las grandes inversiones, los métodos artificiales de planificación familiar todavía tienen limitaciones. Desde la década de 1950, los científicos vienen trabajando para desarrollar un método natural confiable. Este artículo revisa la literatura sobre el Método de Ovulación Billings, presentando su lógica, efectividad, beneficios, desafíos y reglas. Se trata de un método natural, basado en más de cincuenta años de investigación. Su clave es el moco cervical, un indicador confiable de fertilidad, y su efectividad está entre el 97% y el 99%, comparable a los métodos más efectivos. El Método de Ovulación Billings también es adecuado para todo tipo de ciclos, ya que no se fundamenta en cálculos, sino en la observación de mocos. Se concluye que en Brasil es necesario fortalecer programas que ofrezcan una educación sexual más global a la población, además de capacitar a los profesionales de la salud sobre métodos naturales de planificación familiar.

The Fertility Indicator Equation Using Serum Progesterone and Urinary Pregnanediol-3-Glucuronide for Assessment of Ovulatory to Luteal Phase Transition.

Background and Objectives: The Fertility Indicator Equation (FIE) has been shown to signal the fertile phase during the ovulatory menstrual cycle. It was hypothesized that this formulation, a product of two sequential normalized changes with a sign indicating direction of change, could be used to identify the transition from ovulatory to luteal phase with daily serum progesterone (P) and urinary pregnanediol-3-glucuronide (PDG) levels. Materials and Methods: Day-specific serum P levels from two different laboratories and day-specific urinary PDG levels from an additional two different laboratories were submitted for FIE analysis. These day-specific levels included mean or median, 5th, 10th, 90th and 95th percentile data. They were indexed to the day of ovulation, day 0, by ultrasonography, serum or urinary luteinizing hormone (LH). Results: All data sets showed a clear "cluster"-a periovulatory sequence of positive FIE values with a maximum. All clusters of +FIE signaled the transition from the ovulatory to luteal phase and were at least four days in length. The start day for the serum P and urinary PDG FIE clusters ranged from -3 to -1 and -3 to +2, respectively. The end day for serum P and PDG clusters went from +2 to +7 and +4 to +8, respectively. Outside these periovulatory FIE-P and FIE-PDG clusters, there were no consecutive positive FIE values. In addition, the maximum FIE-P and FIE-PDG values throughout the entire cycles were found in the clusters. Conclusions: FIE analysis with either daily serum P or urinary PDG levels provided a distinctive signature to recognize the periovulatory interval. The Fertility Indicator Equation served to robustly signal the transition from the ovulatory phase to the luteal phase. This may have applications in natural family planning especially with the recent emergence of home PDG tests.

The performance of a fertility tracking device.

OBJECTIVE: Fertility tracking devices offer women direct-to-user information about their fertility. The objective of this study is to understand how a fertility tracking device algorithm adjusts to changes of the individual menstrual cycle and under different conditions. METHODS: A retrospective analysis was conducted on a cohort of women who were using the device between January 2004 and November 2014. Available temperature and menstruation inputs were processed through the Daysy 1.0.7 firmware to determine fertility outputs. Sensitivity analyses on temperature noise, skipped measurements, and various characteristics were conducted. RESULTS: A cohort of 5328 women from Germany and Switzerland contributed 107,020 cycles. Mean age of the sample was 30.77 [SD 5.1] years, with a BMI of 22.07 kg/m^2 [SD 2.4]. The mean cycle length reported was 29.54 [SD 3.0] days. The majority of women were using the device 80-100% of the time during the cycle (53.1%). For this subset of women, the fertility device identified on average 41.4% [SD 6.4] possibly fertile (red) days, 42.4% [SD 8.7] infertile (green) days and 15.9% [SD 7.3] yellow days. The number of infertile (green) days decreases proportionally to the number of measured days, whereas the number of undefined (yellow) days increases. CONCLUSION: Overall, these results showed that the fertility tracker algorithm was able to distinguish biphasic cycles and provide personalised fertility statuses for users based on daily basal body temperature readings and menstruation data. We identified a direct linear relationship between the number of measurements and output of the fertility tracker.