Pilot observational prospective cohort study on the use of a novel home-based urinary pregnanediol 3-glucuronide (PDG) test to confirm ovulation when used as adjunct to fertility awareness methods (FAMs) stage 1

Current Ovulation and Luteal Phase Tracking Methods and Technologies for Fertility and Family Planning: A Review

Ovulation is critical for both conception and overall health, but many people who may ovulate are not tracking ovulation or any other part of their menstrual cycle. Failure to track ovulation, especially in those trying to conceive, can lead to fertility challenges due to absent ovulation, mistiming intercourse, or an undetected luteal phase defect. Ovulatory disorders and mistiming intercourse are both primary causes of infertility, and tracking ovulation is shown to decrease the average time to conception. While there are many tracking methods and apps available, the majority are predictive apps or ovulation predictor kits and do not test or track both successful ovulation and the health of the luteal phase, leading to missing information that could contribute to diagnosis or successful conception. Here, we review why ovulation tracking and a healthy luteal phase are important for those trying to conceive. We present currently available ovulation tracking methods that detect both ovulation and the luteal phase, including cervical mucus, urinary hormone testing, and basal body temperature, and discuss the use, advantages, and disadvantages of each. Finally, we consider the role of digital applications and tracking technologies in ovulation tracking.

Comparison of Day-Specific Serum LH, Estradiol, and Progesterone with MiraTM Monitor Urinary LH, Estrone-3-glucuronide, and Pregnanediol-3-glucuronide Levels in Ovulatory Cycles

Background and Objectives: Fertility tracking apps and devices are now currently available, but urinary hormone levels lack accuracy and sensitivity in timing the start of the 6-day fertile window and the precise 24 h interval of transition from ovulation to the luteal phase. We hypothesized the serum hormones estradiol (E2) and progesterone (P) might be better biomarkers for these major ovulatory cycle events, using appropriate mathematical tools. Materials and Methods: Four women provided daily blood samples for serum E2, P, and LH (luteinizing hormone) levels throughout their entire ovulatory cycles, which were indexed to the first day of dominant follicle (DF) collapse (defined as Day 0) determined by transvaginal sonography; therefore, ovulation occurred in the 24 h interval of Day -1 (last day of maximum diameter DF) to Day 0. For comparison, a MiraTM fertility monitor was used to measure daily morning urinary LH (ULH), estrone-3-glucuronide (E3G), and pregnanediol-3-glucuronide (PDG) levels in three of these cycles. Results: There were more fluctuations in the MiraTM hormone levels compared to the serum levels. Previously described methods, the Fertility Indicator Equation (FIE) and Area Under the Curve (AUC) algorithm, were tested for identifying the start of the fertile window and the ovulation/luteal transition point using the day-specific hormone levels. The FIE with E2 levels predicted the start of the 6-day fertile window on Day -7 (two cycles) and Day -5 (two cycles), whereas no identifying signal was found with E3G. However, both pairs of (E2, P) and (E3G, PDG) levels with the AUC algorithm signaled the Day -1 to Day 0 ovulation/luteal transition interval in all cycles. Conclusions: serum E2 and (E2, P) were better biomarkers for signaling the start of the 6-day fertile window, but both MiraTM and serum hormone levels were successful in timing the [Day -1, Day 0] ovulatory/luteal transition interval. These results can presently be applied to urinary hormone monitors for fertility tracking and have implications for the direction of future fertility tracking technology.

A time-resolved fluorescence microsphere-lateral flow immunochromatographic strip for quantitative detection of Pregnanediol-3-glucuronide in urine samples

Introduction: Pregnanediol-3-glucuronide (PdG), as the main metabolite of progesterone in urine, plays a significant role in the prediction of ovulation, threatened abortion, and menstrual cycle maintenance. Methods: To achieve a rapid and sensitive assay, we have designed a competitive model-based time-resolved fluorescence microsphere-lateral flow immunochromatography (TRFM-LFIA) strip. Results: The optimized TRFM-LFIA strip exhibited a wonderful response to PdG over the range of 30-2,000 ng/mL, the corresponding limit of detection (LOD) was calculated as low as 8.39 ng/mL. More importantly, the TRFM-LFIA strip was innovatively used for the quantitative detection of PdG in urine sample, and excellent recovery results were also obtained, ranging from 97.39% to 112.64%. Discussion: The TRFMLFIA strip possessed robust sensitivity and selectivity in the determination of PdG, indicating the great potential of being powerful tools in the biomedical and diagnosis region.

Validation of urinary reproductive hormone measurements using a novel smartphone connected reader

Home use tests to monitor hormone trends during the menstrual cycle have been available over-the-counter for a long time. However, these tests often depend upon manual readouts and hence may lead to false analysis. Furthermore, a lot of these tests are also not quantitative. The aim of this study was to evaluate the accuracy of the quantitative home-based fertility monitor, Inito Fertility Monitor (IFM) and to use it to identify novel hormone trends in natural menstrual cycles. There were two aspects to our analysis: (i) Evaluating the efficacy of Inito Fertility Monitor in the measurement of urinary Estrone-3-glucuronide (E3G), Pregnanediol glucuronide (PdG) and Luteinizing hormone (LH), and (ii) A retrospective study of patients' hormone profiles using IFM. To evaluate the efficacy, the recovery percentage of the three hormones from IFM was evaluated using standard spiked solutions, the accuracy of measurement was calculated and the correlation between reproducible values from IFM and ELISA was established. During the validation of IFM, novel hormone trends were also observed. In order to reinforce the observations, a second group of 52 women was recruited. Assessment of the accuracy of IFM and evaluation of the volunteer urine samples was performed in a laboratory. Home assessment of hormone analysis was carried out using IFM. For the validation study, 100 women aged 21-45 years with cycle lengths ranging from 21 to 42 days were recruited. The participants had no previously diagnosed infertility conditions and their cycle lengths did not vary for more than 3 days from the expected cycle length. Daily first morning urine samples were collected from these 100 women. For the second group, 52 women were selected meeting the same criteria set for the validation study and IFM was provided to these women for testing at home. Coefficient of variation and recovery percentage of IFM with respect to laboratory based ELISA. Percentage occurrence of novel hormone trends and AUC analysis of a novel criteria identified for confirming ovulation. We observed that with all three hormones, IFM had an accurate recovery percentage. We found that the assay has an average CV of 5.05% in PdG measurement, 4.95% in E3G measurement and 5.57% in LH measurement. Furthermore, in predicting the concentration of E3G, PdG and LH in urine samples, we show that IFM has a high correlation with ELISA. In this study, we could also reproduce hormones trends across the menstrual cycle that have been observed by previous studies. We also identified a novel criterion for earlier confirmation of ovulation which could accurately distinguish ovulatory from anovulatory cycles with 100% specificity and had an area under the ROC curve of 0.98. In addition, we identified a new hormone trend which could be observed in 94.5% of the ovulatory cycles. The Inito Fertility Monitor is an effective tool for calculating the urinary concentrations of E3G, PdG and LH and can also be used to provide accurate fertility scores and confirm ovulation. We show that certain hormone trends associated with urinary E3G, PdG and LH could be accurately captured using IFM. In addition, we report a novel criterion for earlier confirmation of ovulation compared to existing criteria. Finally, we present a novel hormone pattern associated with most of the menstrual cycles by examining hormone profiles from the volunteers recruited for the clinical trial.Trial registration: The trial is registered at the current controlled trials ISRCTN registry #ISRCTN15534557.

Using Quantitative Hormonal Fertility Monitors to Evaluate the Luteal Phase: Proof of Concept Case Study

Several new quantitative fertility monitors are now available for at-home use that measure estrogen, luteinizing hormone (LH), and progesterone (PDG) in urine. This case report compares the Mira and Inito quantitative fertility monitors with the well-established qualitative ClearBlue fertility monitor. Three clinical scenarios were evaluated: a normal cycle, a prolonged luteinization cycle, and an anovulatory cycle. The identification of the luteal phase (or lack thereof in the case of anovulation) and the transition through the three processes of luteinization, progestation, and luteolysis were clearly demarcated with the help of quantitative LH and PDG. Quantitative fertility monitors have the potential to identify details of the luteal phase to help women with regular cycles and abnormal luteal phases to help target interventions for optimizing fertility.

Predicting serum hormone concentration by estimation of urinary hormones through a home-use device

STUDY QUESTION

Can a home-use device be used to predict serum hormone levels?

SUMMARY ANSWER

A home-use device can predict urinary hormone values which are well-correlated to serum concentrations of respective hormones and hence can be used as a proxy for serum measurements.

WHAT IS KNOWN ALREADY

Home-use devices that predict ovulation are calibrated against the actual day of ovulation. However, the correlation of any quantitative system to serum hormone concentrations has not been established.

STUDY DESIGN SIZE DURATION

A total of 73 data points obtained from 20 participants across different phases of the menstrual cycle, i.e. bleeding days, follicular phase and luteal phase were used to establish the correlation between serum hormones and urinary metabolite values. Single data points from 20 random users were used to assess the correlation established.

PARTICIPANTS/MATERIALS SETTING METHODS

Participants were women in the fertile age groups and only current users of the home-use device. Selection was done based on inclusion and exclusion criteria. Blood hormones were tested using chemiluminescent immunoassays and urinary measurements were taken on the home-use device at home.

MAIN RESULTS AND THE ROLE OF CHANCE

Serum estradiol (E2), progesterone (P4) and LH were correlated with urinary estrone-3-glucuronide (E3G), pregnanediol glucuronide (PdG) and LH with an R ² of 0.96, 0.95 and 0.98, respectively. Repredicted serum concentration obtained by using the correlation equation had a correlation of 0.92, 0.94 and 0.93 in unknown samples.

LIMITATIONS REASONS FOR CAUTION

The study was designed to include women who have normal cycle lengths regularly; therefore, the values obtained were in the normal range. Certain infertility conditions may cause the values to be higher and correlation in such cases needs to be established.

WIDER IMPLICATIONS OF THE FINDINGS

The results of this study imply a new tool that can be used by fertility specialists as a proxy for blood tests whenever required. Extended study on this system can enable its use in assisted reproductive techniques as well.

STUDY FUNDING/COMPETING INTERESTS

No funding was received for this study. S.P. and D.D. are employees of the research and development division of Samplytics Technologies Pvt. Ltd. which is a forwarder for Inito Inc., USA. A.R. and V.A.V. are co-founders of Inito Inc., USA.

TRIAL REGISTRATION NUMBER

The trial was registered at the International Standard Randomised Controlled Trial Number (ISRCTN) registry (Identifier: ISRCTN15534557).

Complete Cycle Mapping Using a Quantitative At-Home Hormone Monitoring System in Prediction of Fertile Days, Confirmation of Ovulation, and Screening for Ovulation Issues Preventing Conception

Background and Objectives: To achieve pregnancy, it is highly beneficial to identify the time of ovulation as well as the greater period of fertile days during which sperm may survive leading up to ovulation. Confirming successful ovulation is also critical to accurately diagnose ovulatory disorders. Ovulation predictor kits, fertility monitors, and tracking apps are all available to assist with detecting ovulation, but often fall short. They may not detect the full fertile window, provide accurate or real-time information, or are simply expensive and impractical. Finally, few over-the-counter products provide information to women about their ovarian reserve and future fertility. Therefore, there is a need for an easy, over-the-counter, at-home quantitative hormone monitoring system that assesses ovarian reserve, predicts the entire fertile window, and can screen for ovulatory disorders. Materials and Methods: Proov Complete is a four-in-one at-home multihormone testing system that utilizes lateral flow assay test strips paired with the free Proov Insight App to guide testing of four hormones-FSH, E1G, LH, and PdG-across the woman's cycle. In a pilot study, 40 women (including 16 with a fertility-related diagnosis or using fertility treatments) used Complete for one cycle. Results: Here, we demonstrate that Proov Complete can accurately and sensitively predict ovarian reserve, detect up to 6 fertile days and confirm if ovulation was successful, in one easy-to-use kit. Ovulation was confirmed in 38 cycles with a detectable PdG rise. An average of 5.3 fertile days (from E1G rise to PdG rise) were detected, with an average of 2.7 days prior to LH surge. Ovulation was confirmed via PdG rise an average of 2.6 days following the LH surge. While 38/40 women had a PdG rise, only 22 had a sustained PdG level above 5 μg/mL throughout the critical implantation window, indicating ovulatory dysfunction in 16 women. Conclusions: Proov Complete can detect the entire fertile window of up to 6 fertile days and confirm ovulation, while also providing information on ovarian reserve and guidance to clinicians and patients.

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.

Urinary metabolomics reveals the biological characteristics of early pregnancy in pigs

Background

Embryo implantation in sows is an important event during pregnancy. During this process, blastocysts undergo dramatic morphologic changes, and the endometrium becomes receptive. Studies have shown that developmental changes associated with the crosstalk between peri-implantation embryos and embryo-uterine are driven by various biomolecules secreted by the endometrium and embryos. In sows, changes in the uterus are also reflected in circulating body fluids and urine. Metabolomics reveals the metabolic state of cells, tissues, and organisms. In this study, we collected urine samples from large white sows during the peri-implantation period. The levels of urinary metabolites at different periods were analyzed using ultra-performance liquid chromatography/tandem mass spectrometry (UPLC–MS/MS) analysis techniques.

Results

A total of 32 samples were collected from 8 sows during the estrus period and at each phase of early pregnancy (9, 12, and 15 days of gestation). A total of 530 metabolites were identified with high confidence in all samples. Compared with samples collected during the estrus phase, 269 differential metabolites were found in samples obtained during early pregnancy.

Conclusions

The identified metabolites included lipids and lipid-like molecules, organic acids and their derivatives, organic oxygen compounds, organoheterocyclic compounds, benzenoids, among others. Metabolites, such as choline and pregnanediol-3-glucuronide, play important roles in pregnancy in sows and other animals. These results reveal the metabolic changes in urine of sows during early pregnancy phase. The differential urinary metabolites can be used for assessing peri-implantation status in sows. Understanding these metabolic changes may promote the management of pregnant sows through various interventions such as provision of proper nutrition.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40813-022-00256-z.

Descriptive analysis of the relationship between progesterone and basal body temperature across the menstrual cycle

OBJECTIVE

Describe the relationship between basal body temperature (BBT) and pregnanediol-3 alpha-glucuronide (PDG, the urine metabolite of progesterone) across the menstrual cycle.

DESIGN

Observational study.

SETTING

Study carried out from 1996 to 1997 in eight European family planning clinics.

PARTICIPANT(S)

One hundred and seven normally fertile and cycling women.

MAIN OUTCOME MEASURE(S)

BBT and PDG level on each day of 283 cycles and ultrasound determination of the day of ovulation.

RESULT

(s): In comparison with previous end-of-cycle levels, decreases in PDG and BBT on the first day of menses were seen in nearly 90% and 80% of cycles, respectively. In a non-negligible percentage of cycles, luteolysis would continue during menses: between the second and the third day after menses, small but significant decreases in PDG and BBT were seen in 76% and 48% of cycles, respectively. During the peri-ovulatory phase, between the third and the second day before ovulation, PDG and BBT began to rise in 56% and 41% of cycles, respectively. There was a medium degree of correlation between PDG levels and BBT (r = 0.53; 7,279 days with available measurements). The relationship between PDG levels and BBT was linear at low PDG levels but BBT increased no longer when PDG levels continued to rise above a threshold of nearly 10 mcg/mg Cr.

CONCLUSION

(s): PDG and BBT had parallel increases at low PDG rates but diverged at higher rates.

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.

Direct measurement of pregnanediol 3-glucuronide (PDG) in dried urine spots by liquid chromatography-mass spectrometry to detect ovulation

BACKGROUND

Non-invasive self-testing using an objective chemical method to detect ovulation is valuable for women planning conception, practising contraception or undergoing infertility investigations or treatment.

METHODS

Based on luteal phase secretion of progesterone (P₄) and excretion of its major metabolite, pregnanediol glucuronide (PDG), we developed a novel direct liquid chromatography-mass spectrometry (LCMS) method to measure PDG and other steroid glucuronides in urine and in dried urine spots (DUS) without deconjugation or derivatization. Urine PDG by LCMS and immunoassay (P3G) and P₄ by immunoassay with and without adjustment for creatinine were evaluated in daily first void urine samples from 10 women through a single menstrual cycle in which ovulation was confirmed by serial transvaginal ultrasound.

RESULTS

Urine PDG with and without creatinine adjustment was stable during the follicular phase with the expected striking rise in the luteal phase peaking at 5 days after ovulation. Using a single spot urine sample (100 μL) or a DUS (<20 μL urine) and an optimal threshold to distinguish pre- from post-ovulatory samples, in ROC analysis urine PDG adjusted for creatinine accurately identified ovulation in 92 % of samples was comparable with P3G immunoassay and superior to urine P₄ with or without adjustment for creatinine. Extending the analysis to two or three consecutive daily samples reduced the false negative rate from 8% to 2.6 % for two and 1.9 % for three urine samples.

CONCLUSIONS

This method holds promise as a non-invasive self-test method for women to determine by an objective chemical method their ovulatory status.

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.