Accuracy

Lady-Comp, a fertility tracker with a long history

As early as 1983, Dr. Hubertus Rechberg saw the potential of natural family planning and wanted to make it available to every woman, not just a small group. Together with experts in medicine, IT, and design, he built a fertility tracker that combined a temperature sensor with software, laying the foundation for the Fertility Tracker Method (FTM) that today falls under the term FemTech.

More than 40 years have passed since that vision, and the fertility trackers from Valley Electronics have evaluated over 10 million cycles from more than 500,000 women. The current Lady-Comp is the sixth generation. Decades of experience and several scientific studies make it possible to give you highly accurate information about your cycle.

How the algorithm behind Lady-Comp works

The Fertility Tracker Method is based on the calculo-thermal method and combines three elements:

• Recording and learning new data (your daily basal body temperature, the start and end of your period, and your accumulated cycle history) through a fertility tracker.
• Statistically significant evaluation of the post-ovulation temperature rise, using both current and historical data, through an algorithm tuned to the female cycle.
• Eliminating human input and interpretation errors by combining hardware (sensor measurement) and software (algorithm) in a single device.

After a learning phase, the algorithm narrows down your ovulation more and more precisely and sets your fertile window to begin five days before the earliest possible date of ovulation. Once it detects ovulation through the characteristic rise in basal body temperature, it releases individually non-fertile (green) days until your next period. At the end of each cycle, the algorithm re-evaluates its predictions and refines its precision further.

Verified accuracy 

The accuracy of the algorithm was systematically tested in a scientific study and published in a peer-reviewed journal. The study evaluated 107,000 cycles from 5,328 women in Germany and Switzerland over a ten-year period. The result confirms that the algorithm correctly identifies non-fertile (green) days with an overall accuracy of 99.4%. In the study, only 0.6% of the days shown as non-fertile were in fact fertile.

Lady-Comp is FDA-cleared to predict ovulation and identify the days you are most likely to conceive (510(k) K050094).

You can find more information here:

Study "The performance of a fertility tracking device"

Every fraction of a degree matters

Lady-Comp uses a highly sensitive sensor to measure basal body temperature. What makes it special: the sensor waits until the final average temperature is measured. This can take about 60 seconds. The sensor keeps warming until it reaches the final value, and only then is that value stored. Standard thermometers measure faster because they extrapolate the rising curve and estimate the final value.

Lady-Comp waits until the value has stabilized. If the temperature drops in between (for example because cool air enters the mouth while breathing), that value is not used until it rises again and stabilizes. This makes each measurement as precise as possible.

Baby-Comp and Lady-Comp use the same algorithm, developed since 1986. In a field study with the University of Sassari, the device's evaluation matched the clinical methods of ultrasound, urinary LH testing, and blood progesterone measurement across 30 cycles.

More features:

• Ovulation forecast up to 6 days in advance, ideal for planning.
• Recording and documentation of ovulation, which becomes more precise as previous cycles are incorporated.
• During the planning phase you can log when you had intercourse. Lady-Comp evaluates how many cycles this fell within the fertile phase.
• Lady-Comp makes irregularities visible, such as a possible luteal insufficiency or absent ovulation. This can be a valuable basis for a conversation with your gynecologist if conception does not happen.
• Lady-Comp shows a possible pregnancy after 15 days and a likely pregnancy after 18 days.
• Because Lady-Comp knows the likely conception date, it can narrow down your estimated due date and show your week of pregnancy.

Lady-Comp accuracy and quality 

We aim for very high standards. This is why we are continuously working on optimizing all of our products and adapting them to the needs of our users. During the use of Lady-Comp in everyday life, the needs and wishes of users change from time to time, so we always try to find the best possible solution for our users. In order to design and develop a world-class product, we pay as much attention to the little things as to the big things. In the future, too, we will spare neither effort nor expense to ensure that you are always satisfied with your Lady-Comp. Our mission is maximum accuracy and quality for you.

Further Studies

Freundl, G., Frank-Herrmann, P., Godehardt, E., Klemm, R. & Bachhofer, M. (1998). Retrospective Clinical Trial of Contraceptive Effectiveness of the Electronic Fertility Indicator Ladycomp/Babycomp. Advances in Contraception, 14, 97–108. See study

Binkiewicz, P., Michaluk, K. & Demiańczyk, A. (2010). Calculation of the Pearl Index of Lady-Comp, Baby-Comp and Pearly cycle computers used as a contraceptive method. Ginekologia Polska, 81(11). See study

Demiańczyk, A. & Michaluk, K. (2016). Evaluation of the effectiveness of selected natural fertility symptoms used for contraception: estimation of the Pearl index of Lady-Comp, Pearly and Daysy cycle computers based on 10 years of observation in the Polish market. Ginekologia Polska, 87(12). See study

van de Roemer, N., Haile, Y. & Koch, M.C. (2021). European Journal of Contraception and Reproductive Health Care, 26(2): 111–118. See study

Dessole, S., Fadda, M.C., Rosas, N., Scapinelli, A., Inaudi, P. & Ambrosini, A. (1997). Monitoring of ovulation by sophisticated digital electronic BBT recording "Baby-Comp" in patients with unexplained infertility. International Meeting on Infertility and Assisted Reproductive Technology, Porto Cervo, Sardinien, 11.–14. Juni 1997, Program and Abstracts Book, S. 253.