Certification and research confirm Daysy’s safety and quality

Daysy - a medical product to rely on

Daysy has been developed as a medical product and registered accordingly with the CE mark. Not every cycle monitor on the market meets these standards. Unlike Daysy, not all were developed as medical products and are controlled by a quality management system. You can feel confident that Daysy‘s safety and quality are our highest priority.


Daysy’s claim: certification, safety and quality

With Daysy, Valley Electronics AG, based in Switzerland, has developed a medical product that focuses on the woman’s cycle and enables a better understanding of the female body. Valley Electronics AG is certified with EN ISO 13485:2016. This means that our quality management is oriented toward the newest norms for medical products. As the customer, you are at the center of all decisions in product development and manufacturing regarding safety and risk. All procedures at Valley Electronics AG are regularly subjected to internal and external controls. Daysy continues to be supervised after it has been sent to you. This allows us to continuously enhance the quality of the product throughout its entire life cycle.


Important: Daysy is not a „birth control app“ or „birth control computer“. Thanks to their certification, popular „birth control app“ or „birth control computer“ advertise to be in the same class of medical product as the pill. While this is true, there are a number of things to consider with this classification: According to directive 93/42/EWG, medical products that serve as birth control or protection from sexually transmittable diseases are automatically assigned to class IIb. This is the same category of medical product and risk as the pill or a condom. The medical product class gives no indication of the safety of a method of birth control. It indicates the risk to the user’s health in terms of possible side-effects such as infections, intolerance, adhesions, thrombosis or the possible transmission of HIV. This classification has nothing to do with an app’s safety for birth control. As a medical product, Daysy is registered in medical product class I. As such, Daysy is not just entirely free of side-effects, but also bears a significantly lower risk.


Daysy’s Pearl Index

Daysy is based on the same algorithm as the devices by Daysy’s sister company, Valley Electronics GmbH (Germany), that have been in use for over 30 years. The basis of this algorithm has already been studied extensively in Germany in 1997. Over a period of more than 2 years, 686 users in Germany, Switzerland, and Mexico were surveyed about their experiences with the Lady-Comp and the Baby-Comp devices by Valley Electronics GmbH. The study measured a total of 10.601 months, during which 39 unwanted pregnancies were registered. Only 6 of these pregnancies occurred on „green“ days, giving the procedure a method Pearl Index or perfect use Pearl Index of 0,7. The remaining 33 of 39 pregnancies resulted from unprotected intercourse on „red“ or „yellow“ days, resulting in an actual use Pearl Index of 3,8.[1] This Pearl Index was confirmed in two additional studies in 2010 and 2016.[2-3]


How the algorithm behind Daysy works

The database inside each device contains menstrual cycle data of real women. Over 30 years, many different and specific scenarios of menstrual cycles were integrated into the database, including cycles affected by stress, lack of sleep, alcohol and other factors. The algorithm consists of two elements – it records and learns new data (your daily basal body temperature, beginning and end of your period, accumulated data from past cycles) and runs statistical methods (for instance on the increasing temperature after ovulation) to predict the upcoming cycle. This enables it to determine individual infertile (green) days after the menstruation. After a learning phase during which Daysy collects your personal data, the algorithm begins to predict your ovulation and determine your window of fertility, including 5 days before the earliest possible date of ovulation, with increasing precision. For Daysy to determine an increase in temperature, a sustainable and characteristic increase in temperature at the time of ovulation is necessary. Once the algorithm has safely registered your ovulation, it will calculate infertile (green) days until your next period.


A few degrees make the difference

In addition, Daysy uses a very sensitive sensor to measure the basal temperature. Its unique feature is that it waits for the mean temperature value, which can take between 30 and 60 seconds. The sensor warms up before it records your basal temperature to receive a reliable result. Daysy waits until the final temperature value has stabilized. And if the temperature drops during the measurement (for instance due to cold air that gets into the mouth through breathing), the sensor waits for it to rise again and stabilize. This method secures that the measurement is as precise as possible.


The difference between Daysy and common „birth control“ apps

This much is for sure: An app can definitely not be used for birth control! It can merely display a status to its user and let them decide to use birth control or not. Therefore, even the term „birth control“ for an app is misleading.

A grave difference to common birth control apps is that Daysy conveys the recorded data. To use an app, the user needs to additionally purchase a thermometer. Which one is up to them, making it impossible to be certain that it fulfills the necessary standards. This could result in inaccurate measurements and rounding errors, both by the thermometer itself or during transfer of the data into the app. These types of errors can lead to an unwanted pregnancy or the failure to get pregnant. Daysy’s thermo-sensor is an integrated part of the cycle monitor. It is precisely adjusted to the algorithm and covered by the quality management system. Because Daysy does the measuring, recording, and evaluation of your temperature for you, rounding and input errors can be ruled out. In order to appeal to customers, many common birth control apps display a comparatively large amount of „infertile“ days after menstruation even in the first recorded cycle, and without knowing the next ovulation date. Daysy’s algorithm does not take this risk and requires 2-3 cycles to determine green (infertile) days even during the temperature low after menstruation. This requires a little patience, but pays off in safety. Daysy is a one-time investment that comes with no additional cost. Many birth control apps are based on memberships that appear reasonable at first, but in fact bear additional costs for things like thermometers or hormone test kits. This also reflects on the rate of how long an app is being used: According to the newest study [Scherwitzl 2017], after a year, only 56% of women were still using their app. In our currently submitted study, 97% of Daysy cycle monitors are still in use after one year.


Ongoing study on the use of Daysy and DaysyView

In cooperation with the Women’s Clinic at the University Clinic Erlangen, the influence of the app DaysyView on user behavior is currently being studied. 800 users of Daysy from around the world were surveyed. The participants were asked to answer questions about their individual cycle, experience with birth control, pregnancy, family plans and the use and acceptance of the app.

Title: Influence of a mobile application (app) on safety of actual use (Pearl Index) of a cycle monitor used for family planning. Results of a retrospective study

Time period: November 2016 – May 2017

Head of study: Prof. Dr. med. Stefan Renner (Deputy Director of the Women’s Clinic at the University Clinic Erlangen, Universitätsstraße 21-23; 91054 Erlangen)

Research question: The safety of method (perfect) use and actual use of the cycle computer Daysy have already been tested to a Pearl Index of 3,8 and 0,7, respectively, during a clinical study (Freundl et al., 1997). The key question addressed in the current study is whether interest and safety of actual use can be improved through the optional use of a mobile app to display the individual cycle.

Participants: Of 6278 women contacted worldwide, 1969 (31%) reacted to the email. 798 (13%) women filled out the entire survey.

Results: The study, titled „Improving usability and pregnancy rates of a fertility monitor by an additional mobile application: results of a retrospective efficacy study of Daysy and DaysyView App,” has been submitted and is currently being reviewed.

Publication: 1st quarter of 2018


Own research:

1.) Retrospective clinical trial of contraceptive effectiveness of the electronic fertility indicator LadyComp/BabyComp.  [Freundl 1998]

  • Result: Actual use Pearl Index 3.8
  • Method safety: Perfect use Pearl Index 0.7

2.) Calculation of the Pearl Index of Lady-Comp, Baby-Comp and Pearly cycle computers used as a contraceptive method [Binkiewicz 2010]

3.) 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. [Demianczyk 2016]

  • Result: The findings from 1998 were confirmed. 

4.) Improving usability and pregnancy rates of a fertility monitor by an additional mobile application: results of a retrospective efficacy study of Daysy and DaysyView App (submitted in 2017).

  • 800 women took part in this international study.
  • The study was conducted and reviewed by 13 clinical gynecologists from three different universities.


Daysy: we pursue safety, certification and quality all the way!

We want to offer even more than the current standard. That is why we continuously work to optimize Daysy. Needs and preferences can change during the daily use of Daysy, which is why we always strive to find the best solution for our users. To create and develop a world-class product, attention to detail is just as important as the big picture. In the future, we will continue to spare neither cost nor effort to make sure that you are always happy and safe with Daysy! Our mission is maximum safety and quality for you!