Abstract: Systems and methods are provided for characterizing electrical activity of a patient for making a pregnancy-related diagnosis. The system includes a wearable device for measuring an electrical impedance of a cervical tissue of the patient based on a signal applied to the cervical surface by the device. The system also includes a transmitter coupled to the wearable device for transmitting the measured electrical impedance of the cervical tissue to an analysis system for making a pregnancy-related diagnosis based on the impedance data.