File this under perks of PMOS / PCOS

From my experience managing PCOS, I've found that many common fertility tracking apps relying on basal body temperature (BBT) data often cause more confusion than clarity. Apps like Natural Cycles, Tempdrop, and Ava are designed around the assumption of regular ovulatory cycles, which frequently isn't the case for people with PCOS or PMOS. Tracking BBT typically involves noting a slight dip in temperature before ovulation followed by a rise of about 0.5-1°F after ovulation due to progesterone increases. However, because PCOS often involves anovulatory cycles—where ovulation does not occur—many cycles produce a flat temperature curve without that expected rise. This results in charts that don’t show clear fertile windows, making app predictions less reliable or even misleading. I’ve personally seen charts where the temperature stays nearly constant across the cycle or fluctuates randomly, which made it hard to interpret fertility status using BBT alone. Some apps explicitly state that their algorithms work best with cycle lengths between 24-35 days or with consistent ovulation, which automatically excludes a significant number of users with PCOS. For example, Ava's own guidelines mention that many with PCOS may not benefit from its use when trying to conceive. That said, BBT tracking isn’t entirely without value. On cycles where ovulation does occur, a sustained temperature rise can help confirm it post hoc, supporting users in understanding their hormonal patterns. But for predicting ovulation in real time or for irregular cycles, it often falls short. For those managing PMOS/PCOS, combining multiple tracking methods—such as monitoring cervical mucus, hormone testing kits, or ultrasound monitoring—can provide a clearer picture of fertility. It’s also helpful to have a healthcare provider guide interpretation and treatment based on a holistic view rather than relying solely on app-based temperature charts. In short, while BBT tracking apps can be a useful tool, their limitations with PMOS/PCOS highlight the importance of personalized approaches and managing expectations when it comes to fertility tracking.