Period tracking apps and period trackers

Hormone-based cycle computers or ovulation tests measure the concentration of luteinizing hormone (LH) in a woman’s urine and provide information about the timing of ovulation. To practice natural family planning, a barrier method of contraception, such as a condom or diaphragm, must be used during this fertile period. Cycle computers rely on a single measurement per day and require regular cycles that do not exceed 35 days in length. In addition, they require a high degree of discipline (measurements must be taken at the same time every day) and a consistent lifestyle (stress, sleep, and alcohol can skew the results).

The ovulation test is based on the assumption that, once the egg reaches a certain stage of maturity, a surge of the hormone LH is released, thereby triggering ovulation. Until now, it was assumed that ovulation occurs approximately 24 to 48 hours after a prolonged LH surge. However, studies have shown that there are various patterns of LH levels that can vary from cycle to cycle, but also from woman to woman (Diereito 2012).*

The study shows that there is a wider range of LH profiles than previously thought. On average, the LH peak occurred 1.2 days after ovulation, rather than before ovulation as expected. In only 6% of cycles did the LH surge end before ovulation. In the vast majority (94%), however, LH continued to rise after ovulation, and in 60% of cycles, it even rose for longer than 3 days.