Clinical Validation

Characterization of Urine Pregnanediol rapid test and its use for confirming ovulation


Lack of or insufficient ovulatory events is the primary cause of infertility worldwide and with 12% of couples within the US being diagnosed with infertility each year (according to the CDC), thus being able to confirm ovulation is an essential component of infertility evaluations in women. The gold standards for confirming ovulation include transvaginal ultrasounds and serum progesterone blood draws. Both of these techniques are too invasive, too expensive, and/or inaccessible to most women. Therefore a non-invasive, inexpensive, home-based testing system to confirm ovulation is desired. Several recent studies have identified urinary pregnanediol levels as an accurate way to confirm ovulation. However, until now, urine pregnanediol levels were always measured via a lab setting. Here we describe the development of a urine pregnanediol (PDG) rapid test and its use at confirming ovulation in a home environment.

Study Protocol

One hundred and ninety six women are recruited to take part in a prospective, blinded cohort home environment study. The study protocol was approved by the Ethics Committee at Solutions IRB. Detailed information about the study was provided to each volunteer, and informed consent was obtained prior the study commencement. Inclusion criteria were non-pregnant women residing within the United States, aged 18- 45, and not currently on hormonal birth control. Importantly, women were not excluding due to average cycle length, weight (BMI), breastfeeding status, poly-cyctic ovarian syndrome (PCOS) or any other cause of infertility or lifestyle factor.

Volunteers were asked to predict ovulation by monitoring changes in cervical mucus and/or tracking luteinizing hormone (LH) via home test kits. Volunteers were asked to self-report their peak fertility day, which was defined as the first LH surge day and/or day of peak cervical mucus (stretchy and eggwhite in consistence). Volunteers collected first morning urine as various times during their cycle, including, prior to, during, and after peak fertility signs were observed.

Volunteers were provided PDG rapid response test strips and self-administered their tests and recorded their results. Test results were reported back researchers via a log sheet. Log sheets recorded testing date, day of cycle, date of peak fertility (if known), personal assessment of results (positive result vs negative result) and a place to tape the completed test strip.


Data was collected from 190 unique cycles. Due to the unique character of the test (single line being a positive test result and two lines being a negative result) and first determines if volunteers were able to read the results properly. To do so, log sheets were read by trained scientists and compared to lay users assessments. In over 99% of cases, the trained professional and layperson arrived at the same conclusion. This suggests that home users can accurately read the PDG rapid tests.

In the 190 cycles, only one person reported observing a positive PDG test result prior to peak fertility observation. On the other hand in 28 of the cycles, volunteers were unable to achieve positive PDG test results after peak fertility was observed.

Thus we show that a single threshold urine pregnanediol rapid test was able to confirm ovulation in over 85% of cycles studied.


Basal body temperature (BBT) is often used to confirm ovulation in a home environment due to its low cost. However the accuracy of BBT to confirm ovulation is difficult and very challenging for some women. Most women have a BBT shift of only 0.28 to 0.56 degree C and can be affected by sleep quality, time zones changes, alcohol, and wake time. These factors make BBT tracking only 66% accurate at confirming ovulation. Additionally, BBT charting doesn’t give women any information on the level of progesterone, thus making BBT incapable of determining infertility due to insufficient ovulatory events. We show here that urine progesterone rapid test were able to confirm ovulation in 85% of cycle and gave women important information on the level of progesterone produced after ovulation.

Interestingly, we were unable to confirm ovulation via our single threshold urine pregnanediol rapid test in 14.7% of the cycles studied. In most cases, these women were able to see raising levels of PDG as indicated by the decreasing intensity of the test line. However, the test never truly turned positive in these 28 cycles. These results could be due to low progesterone, which occurs in ~10% of women. Another cause of these results could be the way progesterone is metabolized into PDG, hydration status, or not having held urine long enough prior to testing.

Unlike most fertility tracking validation studies, our study design did not exclude volunteers based on irregular cycles, breastfeeding status, PCOS diagnosis, or other cause of infertility. Therefore, we show that urine pregnanediol is a useful diagnostic tool for evaluating ovulation in not only normal women but also in lactating women and women with PCOS, two populations of women that currently lack accurate ovulation tracking tools.

MFB Fertility was founded by scientists dedicated to empowering women to take control of their fertility. We developed our Proov test after searching through all current research studies in order to develop the most accurate product. Below are some of the most important studies on PdG that were used to develop our Proov test and set its threshold value.