For decades, the hormonal fluctuations that characterize the female reproductive cycle have been viewed as a confounding factor, contributing to the exclusion or underrepresentation of women in preclinical and clinical research. Today these same fluctuations are increasingly recognized as a valuable source of information about women’s overall health.

Interest in this field has grown in recent years, driven by wearable devices that continuously monitor physiologic parameters and algorithms that analyze these data to identify health-related patterns. The rapid expansion of telemedicine during the COVID pandemic further accelerated this trend.

Growing Industry

Worldwide, about 4300 companies currently operate in the FemTech sector, which encompasses technology products and services designed to support women’s health, including devices and apps that predict ovulation and menstruation.

The global FemTech market is projected to exceed US$97 billion by 2030. Beyond reproductive health, the industry is expanding its focus to identify novel biomarkers and develop tools for the prevention, diagnosis, and monitoring of conditions such as endometriosis, polyendocrine metabolic ovarian syndrome (formerly known as polycystic ovary syndrome), ovarian cancer, and cardiovascular disease.

This development could help reduce longstanding gender-based disparities in biomedical research and healthcare, provided that key challenges are addressed, including rigorous scientific validation of emerging technologies and robust protection of users’ privacy.

Temperature Biomarker

One example of an emerging FemTech application was reported in Science Advances by researchers at SRI International, Menlo Park, California, a nonprofit research institute in the US. The researchers developed an algorithm called Women’s Health Assessment Through Variability in Endocrine-related Signals (WAVES) and used it to analyze a database compiled in the 1990s containing daily basal body temperature (BBT) recordings from more than 5600 menstrual cycles among 753 women aged 18-42 years.

BBT, the body’s resting temperature, typically measured immediately after waking, undergoes subtle physiologic changes throughout the menstrual cycle in response to hormonal fluctuations. Monitoring these changes has long been used to determine whether ovulation has occurred. Today wearable devices can continuously monitor skin temperature during sleep, allowing users to estimate the BBT and track changes over time without taking daily measurements after waking.

Using the WAVES algorithm, the authors identified the characteristics of BBT curves that appeared to be associated with advancing age. They also proposed that the same approach could identify patterns associated with the disease, potentially supporting earlier diagnosis and disease monitoring.

Regulatory Challenges

Despite these advances, the rapidly growing FemTech sector faces several important challenges, beginning with regulations.

In the US, where many FemTech products originate, the FDA regulates products according to their intended use, as defined by the manufacturer. Devices and apps marketed for medical purposes, such as identifying the fertile window to support contraception, conception, or disease diagnosis, must meet safety and effectiveness requirements. In contrast, products marketed as wellness tools or for monitoring normal physiologic functions generally do not require authorization despite their widespread use.

As a result, currently a gray area exists in the US market, where many products have not undergone regulatory review, even though women may rely on them when making important reproductive health decisions. A similar situation exists in the EU, where apps and devices that do not claim diagnostic, preventive, or therapeutic purposes can be marketed without formal evaluation of their safety or performance.

Privacy Concerns

Thus, privacy is a major concern. In the US, physiologic data collected by wearable devices and analyzed by apps are protected by federal health privacy laws only when they are handled within the information systems of healthcare providers, hospitals, or health insurers. In many cases, FemTech companies store these data on their own servers rather than within the healthcare system, placing them outside the scope of these protections. Data may also be shared with third parties for targeted advertising, market analysis, user profiling, or product development.

After the US Supreme Court’s June 2022 ruling in the Dobbs v. Jackson Women’s Health Organization, experts warned that data from menstrual tracking apps could be used as evidence in investigations under state abortion laws.

For example, a missed menstrual period recorded by an app, combined with travel to a state where abortion is legal and the subsequent return of menstruation, could be interpreted as evidence of an induced abortion.

In the EU, information collected by FemTech apps and devices is protected under the General Data Protection Regulation. However, the regulation does not prohibit the collection or commercial use of health data. When users provide valid consent, companies can process the information in accordance with their privacy policies. Consequently, concerns remain regarding the transparency of privacy policies, data sharing with commercial partners, and whether users fully understand how their data may be used.

The challenge in the coming years is to transform the vast amount of data generated by FemTech into clinically useful tools without compromising scientific rigor, transparency, or privacy. Only then can the information collected daily by millions of women become a meaningful resource for improving women’s health, rather than a source of new inequalities and risks.

This story was translated from Univadis Italy.