In order to support the desire to have children, the first step is to determine the women’s cycle. This knowledge helps to determine the optimal time for natural family planning (NFP) or intrauterine insemination (IAI). For this first stage of fertility treatment either the hormone level can be tested or the temperature (basal temperature or body core temperature) recorded.
The recording of the temperature for the determination of the female cycle should ideally take place over a longer period of time during sleep. Measurements with a conventional clinical thermometer not only provide more or less accurate temperature data depending on the measuring place but also only one-time readings. Due to not being able to measure the basal temperature directly in the night, it is recommended to take the women´s temperature right after waking up. Various algorithms then try to calculate back to the minimum core temperature which is always reached at night.
Previously available solutions for the direct measurement of basal body temperature at night (e.g. bracelets, vaginal ring thermometers) are either not suitable for a precise determination of ovulation or must be worn almost continuously inside the body. It is possible for women to measure the hormone level in their urine at home, but it must be integrated into the daily routine and is therefore often associated with a great deal of effort.