Labor Status Monitor for Diagnosing True vs False Labor in Preterm Patients

This is a multicenter device optimization study, conducted as an observational cohort study.

All subjects will self-present for evaluation of threatened preterm labor. Threatened labor is defined here to mean that the diagnosis of in-Labor or Not-in-Labor is uncertain based on an initial evaluation. In practice, this means that the patient is experiencing uterine contractions, although her cervix is not dilated (opened) sufficiently for her to be immediately diagnosed as in-Labor and it is unclear if delivery will result from these contractions.

Current methods use legacy fetal monitoring devices to assist with making a working diagnosis of in-Labor or Not-in-Labor. Clinical management is then based on the working diagnosis. Legacy fetal monitoring devices are usually a tocodynamometer (Toco) and Doppler but alternately may be any FDA-cleared fetal monitor. There are several EMG-based FDA-cleared fetal monitors, although none are approved for use in preterm patients < 37 weeks.

With threatened labor, current methods typically require 2 to 4 hours to diagnose labor status (in-Labor or Not-in-Labor), although longer durations of evaluation are common. The Labor Status Monitor is designed to make a diagnosis using EMG within 1 to 2 hours, and with greater sensitivity and specificity than current methods. To establish the duration of recording needed to make a diagnosis with the Labor Status Monitor, EMG recording will be performed for at least 1 hour, and up to the time required to make the diagnosis using current methods.

The Labor Status Monitor uses electromyography (EMG) sensors that were specifically designed to record EMG from the pregnant uterus. These custom sensors are called "Area Sensors" since they report the EMG signal from a local area of the uterus. An array of 6 Area Sensors distributed widely across the front of the abdomen is used to depict the activity of the entire uterus.