on April 02, 2026
The Lady-Comp story starts with a personal problem. More than 35 years ago, the wife of Dr. Hubertus Rechberg was experiencing increasingly difficult side effects from the contraceptive pill. Concerned for her health, Dr. Rechberg set out to find a better alternative. He studied every natural family planning method available at the time, analysed each one carefully, and concluded that none of them were good enough.
So he decided to build something himself. His solution combined a precision thermal sensor with a sophisticated computer, running software built on all the NFP (Natural Family Planning) rules known at the time. The result could generate cycle statistics and display reliable fertility indicators, something that had never existed in a single handheld device before.
In 1986, Dr. Rechberg founded Valley Electronics GmbH. Working alongside a team of gynaecologists, software engineers, electrical engineers, and designers, Valley Electronics brought Baby-Comp to life: the world's first mini-computer capable of analysing the menstrual cycle. It came in black or white, featured a straight thermal sensor, and was considerably larger than the devices we know today.
The first clinical trial took place in 1988 at the Frauenklinik Benrath of the University of Düsseldorf, home to Germany's leading natural family planning research team at the time. Under the direction of Prof. Dr. G. Freundl, the Baby-Comp was put to the test. The thermal sensor demonstrated a deviation of just 0.05 degrees Celsius, and clinical safety testing confirmed the device performed exactly as its developers had intended.
New research findings led to a redesign, and in 1998 a slimmer, more modern model was introduced alongside a new name: Lady-Comp. Like the Baby-Comp before it, Lady-Comp featured a removable, ergonomically curved sensor. It was designed specifically for women who wanted hormone-free family planning, and it was simpler to use than anything that had come before it.
Over the following years, Dr. Rechberg and his team continued refining the method, prioritising accuracy and reliability above all else. Lady-Comp was subjected to a series of rigorous independent studies led by some of Europe's foremost fertility experts:
- 1992 Prof. Martinez, Amsterdam, Netherlands
- 1992 Prof. Freundl, Barcelona Congress, Spain
- 1994 Prof. Wildt, Erlangen, Germany
- 1997 Prof. Dessole, Sassari, Italy
In 1998, Prof. Freundl led a landmark Pearl Index study at the Benrath Women's Clinic in Düsseldorf, drawing on 10,000 cycles from Lady-Comp and Baby-Comp users across Switzerland, Germany, and Mexico. All unplanned pregnancies were independently reviewed and analysed by external researchers.
The most recent Lady-Comp model launched in February 2021, bringing a refreshed design and new features while building on more than three decades of research and development. Today, both Lady-Comp and Daysy achieve 99.4% accuracy in identifying green (infertile) days. The research continues, and the story is far from finished.
Ready to experience over 35 years of innovation for yourself? Discover the Lady-Comp fertility monitor or explore the app-connected Daysy fertility tracker and take control of your cycle naturally.
