In this study physiological data is measured using wearable sensors as well as hormonal and ultrasound measurements of growing follicles/ ovulation in a group of endocrinologically healthy women with regular cycles, who aim for a spontaneous pregnancy. These women were recruited to generate reliable data on changes of the measured physiological parameters in a healthy menstrual cycle, as well as to evaluate physiological changes associated with early pregnancy.

All pregnancies beginning during the study period are to be monitored to their natural end, in order to evaluate how the same nine physiological parameters are changing during pregnancy, how strong the variations of the parameters during pregnancy are, and whether they could be associated with early onsets of pregnancy complications such as premature birth or pre-eclampsia. This will be highly valuable to develop study protocols for the specific evaluation of the screening potential of pregnancy complications.

Inclusion Criteria:

• women aged 20-40 years
• regular menstrual cycle (28 days+/-)
• no hormonal therapy
• German-speaking
• written informed consent to participate in the study

Exclusion Criteria:

• any health-related issues that may affect menstrual cycle
• any consumption of medication or other substances that may affect the menstrual cycle or any of the physiological parameters investigated
• frequent travel between time zones
• sleeping disorders
• unsuccessfully trying to conceive for > 12 months

In this study we want to conduct measurements of physiological data as well as hormonal and ultrasound measurements of growing follicles/ ovulation in a group of endocrinologically healthy women with a regular cycle, who aim for a spontaneous pregnancy. We choose these women to generate reliable data on changes of the measured physiological parameters in a healthy menstrual cycle, as well as to evaluate physiological changes associated with the initiation of pregnancy.

We want to continue measurements in all pregnancies beginning during the study period to evaluate how the same nine physiological parameters are changing during pregnancy, how strong the variations of the parameters during pregnancy are, and whether they could be associated with early onsets of pregnancy complications such as premature birth or preeclampsia. This will be highly valuable to develop study protocols for the specific evaluation of the screening potential of one of the pregnancy complications.