Devices, systems and methods are described herein that enable and make assessments related to pregnancy, including assessments related to a labor-related status such as the onset of true labor. In some embodiments, a pregnancy monitoring system comprises a portable, noninvasive data acquisition device adhered to a patient's skin, comprising at least two electrodes to measure uterine electrical activity, signal processing means, data storage means, and a battery. Systems for notification of the labor-related status are described.