A multi-sensor patch for simultaneous abdominal monitoring of maternal and fetal physiological data includes a multi-layer flexible substrate. The multi-layer flexible substrate includes a center region and a plurality of electrode regions. An electrode of the plurality of electrodes is located in each of the electrode regions. At least one auxiliary sensor which may be an optical sensor. A module unit is connected to the conductive layer at the center region. The module unit is configured to receive biopotential physiological data from the plurality of electrodes and photosignal data from the optical sensor. The module unit calculates at least fetal heart rate (fHR), maternal heart rate (mHR), and uterine activity (UA) from the biopotential physiological data and fHR, mHR, and SpO2 from the photosignal data.