Fertility Awareness · Technology
Abstract
Objectives
To characterize how commercially available fertility-tracking devices and wearables define ovulation and anovulation, evaluate available comparator evidence, and assess user burden across 19 selected technologies.
Study Design
We conducted a structured landscape analysis of 19 fertility-tracking devices and wearables available in the United States. Technologies were evaluated for biomarker type, operational definitions of ovulation and anovulation, comparator evidence, intended use, regulatory status, and user burden, among other variables.
Results
Technologies clustered into four major categories: luteinizing hormone (LH)-only devices, multi-hormone devices, basal body temperature (BBT)-based wearables, and BBT-based thermometers. LH-only devices generally defined ovulation by detecting an LH surge or peak; multi-hormone devices incorporated LH and/or pregnanediol-3-glucuronide (PdG) measurements; and BBT-based technologies relied on thermal shifts. Explicit definitions of anovulation were uncommon and were frequently inferred from the absence of ovulation-associated biomarkers. The existence and design of comparator evidence varied substantially across technologies. Most comparator studies relied on surrogate measures such as urinary or serum hormones, whereas few technologies had comparator evidence against physiological reference standards such as transvaginal ultrasound (TVUS). Comparator studies in irregular-cycle populations were uncommon despite frequent marketing of these devices as appropriate for users with irregular cycles. User burden varied substantially across technologies.
Conclusions
Fertility-tracking technologies demonstrate substantial heterogeneity in operational definitions, comparator evidence, and user burden. Greater transparency regarding ovulation and anovulation definitions, clearer reporting of comparator evidence, and more representative evaluation in irregular-cycle populations are needed to support accurate interpretation and integration into reproductive healthcare.
Topics
By this author
Long Acting Methods · Intrauterine Devices
PASS, VAS, or satisfaction: A prospective observational study of IUD placement pain experiences
McAllaster S et al., 2026 · Contraception
To identify factors associated with unacceptable Patient Acceptable Symptom State (PASS) responses, Visual Analog Scale (VAS) scores, and satisfaction at time of intrauterine device (IUD) placement. Recruitment occurred at six Utah clinics between 6/24-2/25. Participants completed procedure surveys on demographics, reproductive history, anticipated pain, anxiety, and coping skills. Post-placement surveys assessed PASS responses, experienced pain by VAS (1-100mm) and satisfaction with IUD placement (5-point Likert scale). We determined factors associated with unacceptable PASS responses and a cut point delineating "low" vs "high" pain to assess measure associations. Of 194 participants, 21% (n = 41) reported an unacceptable PASS, which was associated with higher mean anticipated (65 mm vs 51 mm; padj=0.01) and experienced (76 mm vs 46 mm; padj<0.001) pain, prior sexual assault (55% vs 28%; padj=0.016), or violent death of someone close (25% vs 7%; padj=0.024). In controlled analysis, higher experienced pain predicted unacceptable PASS (OR:1.10;95%CI:1.06, 1.14). "High" pain (≥61mm) occurred in 44% of all participants. Of those with high pain, 55% reported an acceptable PASS response. History of prior pelvic exam (p = 0.02, padj 0.20), prior IUD placement (p = 0.003; padj 0.12), or violent death of someone close (p = 0.011; padj 0.13) influenced unacceptable PASS responses in this group. Of all participants, 21% reported dissatisfaction (n = 16) or neutral response (n = 24) regarding their IUD placement, among which only 13 reported an unacceptable PASS (32%). Satisfaction was influenced by mean VAS score (61 mm dissatisfied/neutral vs 50 mm satisfied; p = 0.01; padj 0.90). IUD placement pain level may influence satisfaction, but less than half of those with high pain (≥61mm) reported an unacceptable experience. IUD placement pain experiences are multi-dimensional and cannot be described by pain level alone. High levels of placement pain influence satisfaction and overlap but are not collinear with acceptability responses. Acceptability of IUD may be subject to temporal bias and influenced by whether their goals/needs are met and whether the pain was ultimately worth it.
Experiences of healthcare providers caring for pregnant individuals with substance use disorder
Nantume A et al., 2025 · Drug and alcohol dependence · Free full text on PubMed Central
Substance use disorder (SUD) during pregnancy is associated with an increased risk of adverse maternal and neonatal outcomes, yet many patients face significant barriers to accessing treatment, including experiencing bias and stigma from healthcare providers. To inform improvements in care delivery, this study explored the experiences of healthcare providers who care for pregnant individuals with SUD. Researchers conducted seven focus group discussions (FGD) and fifteen in-depth interviews (IDI) using semi-structured guides, with participants drawn from both rural and urban hospital settings across Utah. All discussions were audio recorded, transcribed verbatim, and examined using the Template Analysis approach. Among FGD participants (n = 37), the sample was predominantly white (94.6 %), female (86.5 %), rural (89.2 %), and comprised of nurses (78.4 %). The IDI sample (n = 15) was more gender diverse (60 % female), had greater representation of physicians (53.3 %), and a higher proportion of urban participants (60.0 %). Template analysis revealed four major themes. First, providers held a range of perceptions toward pregnant individuals with SUD, reflecting both stigma and empathy. Second, many emphasized the importance of building trust through nonjudgmental communication and emotional support. Third, providers reported high levels of burnout, particularly due to limited resources and systemic barriers. Finally, participants highlighted knowledge gaps related to SUD clinical care and confusion around regulatory requirements like mandatory reporting. Despite the challenges described, many providers expressed strong dedication to delivering compassionate, person-centered care. The findings underscore the need for targeted provider education, institutional policies that reduce care barriers, and increased community and institutional resources to better support patients with SUD during pregnancy.
Effectiveness · Typical and Perfect Use
Evaluating Pregnancy Rates in Fertility Awareness-Based Methods for Family Planning: Simulated Comparison of Correct Use to Avoid, Method-Related, and Total Pregnancy Rates
Stanford JB et al., 2024 · Linacre Q · Free full text on PubMed Central
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. 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 In FABM studies, the method-related pregnancy rate is biased too low, but the correct use pregnancy rate is unbiased.
Workflow and Documentation · Charting Systems and Records
Pregnancy Risk Screening and Counseling for Women Veterans: Piloting the One Key Question in the Veterans Healthcare Administration
Gawron LM et al., 2021 · Southern medical journal
Women veterans have a high prevalence of comorbidities that increase the risk of adverse pregnancy outcomes. Screening for pregnancy desires in primary care provider (PCP) visits offers an opportunity to optimize preconception health. This pilot quality improvement initiative sought to assess Veterans Healthcare Administration provider preferences on One Key Question (OKQ) implementation, identification of veterans' reproductive needs, and the effect of training on documentation in a women's primary care clinic in Salt Lake City, Utah. We hosted OKQ training sessions for providers and staff, audio recorded group discussions on implementation barriers, and explored themes. Women veterans presenting for a PCP visit in July 2018 self-completed a paper OKQ screening tool. We calculated summary statistics on responses. We conducted a pre-post analysis, with respect to training sessions, to measure for changes in family planning documentation during PCP visits. Nineteen providers and staff completed the training. They acknowledged the importance, but believed that the screening tool should be completed by veterans and not be provider prompted. Forty-two women veterans completed the screening tool: 21% desired pregnancy in the next year and 26% desired contraceptive information. Chart reviews found a nonsignificant increase in current contraceptive method documentation between periods (20% vs 37%; P = 0.08), a decline in documentation of reproductive goals (22% vs 3%; P = 0.02), and no significant change in counseling. Veterans identify reproductive needs via the OKQ screening tool, but provider documentation did not reflect changes in care following training. Further study is necessary to develop an optimal, patient-centered tool and implementation plan to support women veterans in their reproductive goals.
Related research
Technology · Cycle Tracking Apps
Helping Patients to Predict and Confirm Ovulation with the Use of Combined Urinary Hormonal and Smartphone Technology: A Proof-of-Concept Retrospective Descriptive Case Series
Leiva R et al., 2024 · Seminars in reproductive medicine · Free full text on PubMed Central
Smartphone-based fertility awareness methods with home-based urinary hormonal testing are gaining popularity for fertility tracking. In our university-affiliated family practice, we integrated a previously developed ovulation tracking application into a protocol for monitoring urinary sex hormones and cervical secretions. Serum progesterone was used to confirm the luteal phase, with levels ≥ 15.9 nmol/L ensuring confirmation. Data from 110 women seen for infertility treatment (n = 95) or family planning advice (n = 15) and using our ovulation prediction protocol showed that most opted for a combination of cervical mucus and luteinizing hormone testing (n = 86). Among those using it for family planning, the median usage among women spanned 56 cycles, and 13 cycles per woman required progesterone testing for confirmation. Thirteen patients are still using the method without unintended pregnancies. No unintended pregnancies occurred. Confidence in tests based on serum progesterone was high (93%). For infertility, the method helped in the identification of anovulation, evaluating treatment response, and in diagnosing subfertility causes. This proof-of-concept retrospective descriptive case series suggests the potential for smartphone-based monitoring in fertility management, urging further studies for application enhancements and prospective validation.
Biomarkers · Urinary Hormone Monitoring
Pulse Rate Measurement During Sleep Using Wearable Sensors, and its Correlation with the Menstrual Cycle Phases, A Prospective Observational Study
Shilaih M et al., 2017 · Sci Rep · Free full text on PubMed Central
An affordable, user-friendly fertility-monitoring tool remains an unmet need. We examine in this study the correlation between pulse rate (PR) and the menstrual phases using wrist-worn PR sensors. 91 healthy, non-pregnant women, between 22-42 years old, were recruited for a prospective-observational clinical trial. Participants measured PR during sleep using wrist-worn bracelets with photoplethysmographic sensors. Ovulation day was estimated with "Clearblue Digital-Ovulation-urine test". Potential behavioral and nutritional confounders were collected daily. 274 ovulatory cycles were recorded from 91 eligible women, with a mean cycle length of 27.3 days (±2.7). We observed a significant increase in PR during the fertile window compared to the menstrual phase (2.1 beat-per-minute, p < 0.01). Moreover, PR during the mid-luteal phase was also significantly elevated compared to the fertile window (1.8 beat-per-minute, p < 0.01), and the menstrual phase (3.8 beat-per-minute, p < 0.01). PR increase in the ovulatory and mid-luteal phase was robust to adjustment for the collected confounders. There is a significant increase of the fertile-window PR (collected during sleep) compared to the menstrual phase. The aforementioned association was robust to the inter- and intra-person variability of menstrual-cycle length, behavioral, and nutritional profiles. Hence, PR monitoring using wearable sensors could be used as one parameter within a multi-parameter fertility awareness-based method.
Effectiveness · Comparative Effectiveness
A Comparison of Two Hormonal Fertility Monitoring Systems for Ovulation Detection: A Pilot Study
Mu Q et al., 2023 · Medicina (Kaunas) · Free full text on PubMed Central
Background and Accuracy in detecting ovulation and estimating the fertile window in the menstrual cycle is essential for women to avoid or achieve pregnancy. There has been a rapid growth in fertility apps and home ovulation testing kits in recent years. Nevertheless, there lacks information on how well these apps perform in helping users understand their fertility in the menstrual cycle. This pilot study aimed to evaluate and compare the beginning, peak, and length of the fertile window as determined by a new luteinizing hormone (LH) fertility tracking app with the Clearblue Fertility Monitor (CBFM). A total of 30 women were randomized into either a quantitative Premom or a qualitative Easy@Home (EAH) LH testing system. The results of the two testing systems were compared with the results from the CBFM over three menstrual cycles of use. Potential LH levels for estimating the beginning of the fertile window were calculated along with user acceptability and satisfaction. The estimates of peak fertility by the Premom and EAH LH testing were highly correlated with the CBFM peak results (R = 0.99, p < 0.001). The participants had higher satisfaction and ease-of-use ratings with the CBFM compared to the Premom and EAH LH testing systems. LH 95% confidence levels for estimating the beginning of the fertile window were provided for both the Premom and EAH LH testing results. Our pilot study findings suggest that the Premom and EAH LH fertility testing app can accurately detect impending ovulation for women and are easy to use at home. However, successful utilization of these low-cost LH testing tools and apps for fertility self-monitoring and family planning needs further evaluation with a large and more diverse population.
Technology · Wearable Devices
Nocturnal finger skin temperature in menstrual cycle tracking: ambulatory pilot study using a wearable Oura ring
Maijala A et al., 2019 · BMC Womens Health · Free full text on PubMed Central
Body temperature is a common method in menstrual cycle phase tracking because of its biphasic form. In ambulatory studies, different skin temperatures have proven to follow a similar pattern. The aim of this pilot study was to assess the applicability of nocturnal finger skin temperature based on a wearable Oura ring to monitor menstrual cycle and predict menstruations and ovulations in real life. Volunteer women (n = 22) wore the Oura ring, measured ovulation through urine tests, and kept diaries on menstruations at an average of 114.7 days (SD 20.6), of which oral temperature was measured immediately after wake-up at an average of 1.9 cycles (SD 1.2). Skin and oral temperatures were compared by assessing daily values using repeated measures correlation and phase mean values and differences between phases using dependent t-test. Developed algorithms using skin temperature were tested to predict the start of menstruation and ovulation. The performance of algorithms was assessed with sensitivity and positive predictive values (true positive defined with different windows around the reported day). Nocturnal skin temperatures and oral temperatures differed between follicular and luteal phases with higher temperatures in the luteal phase, with a difference of 0.30 °C (SD 0.12) for skin and 0.23 °C (SD 0.09) for oral temperature (p < 0.001). Correlation between skin and oral temperatures was found using daily temperatures (r = 0.563, p < 0.001) and differences between phases (r = 0.589, p = 0.004). Menstruations were detected with a sensitivity of 71.9-86.5% in window lengths of ±2 to ±4 days. Ovulations were detected with the best-performing algorithm with a sensitivity of 83.3% in fertile window from - 3 to + 2 days around the verified ovulation. Positive predictive values had similar percentages to those of sensitivities. The mean offset for estimations were 0.4 days (SD 1.8) for menstruations and 0.6 days (SD 1.5) for ovulations with the best-performing algorithm. Nocturnal skin temperature based on wearable ring showed potential for menstrual cycle monitoring in real life conditions.
Fertility Awareness › Technology › Wearable Devices · Research Methods › Evidence Synthesis › Systematic Reviews · Menstrual Cycle › Cycle Biomarkers › Hormonal Markers
Bryce Wallis, Danielle L Lehto, Ishor Thapa, Chelsea B Polis, Rebecca G Simmons
B Wallis, D Lehto, I Thapa, C Polis, Becky Simmons, R Simmons
PMID 42641906 42641906 DOI 10.1016/j.contraception.2026.111577 10.1016/j.contraception.2026.111577 Wallis et al. 2026, Wallis 2026