We have designed new electromyography sensors for measuring uterine activity. These sensors are directional - they preferentially report uterine muscle contractions at specific locations, called regions. By measuring the synchronization of the regions of the uterus during contractions we intend to non-invasively determine if any patient is in-labor or not-in-labor. Accurately diagnosing true preterm labor allows timely intervention to avoid preterm birth; Accurately diagnosing false preterm labor avoids needlessly treating patients who would not benefit.

The legacy device for assessing uterine contractions is the tocodynamometer (Toco). The Toco is plunger-driven device that measures the uterine shape change that occurs with a contraction. Toco only reports the timing of contractions, not the contraction strength, and cannot distinguish between false and true labor.

Our overarching goal is to validate our method of determining if a patient experiencing contractions is in true labor or false labor. We will accomplish this by applying new knowledge to an old technology - uterine EMG.

This trial is based on our advanced understanding of how the uterus generates coordinated contractions without a pacemaker or dedicated electrical conduction pathways - mechanotransduction and intrauterine pressure - but also uses bioelectrical signaling for local tissue recruitment.

The uterus emits bioelectrical signals with each contraction that can be detected by electromyography (EMG). To observe uterine bioelectrical signals, we created a novel EMG sensor, we call the "area sensor". This sensor is directional - capable of preferentially reporting muscle contractions from immediately below the sensor location.

In this clinical trial we use multiple area sensors placed on the maternal abdomen to directly observe how well the regional contractions are synchronized. Our hypothesis to be tested is that highly synchronized contractions predicts true labor, unsynchronized predicts false labor.

Patients with unclear labor status, or those in early labor will be studied. We will correlate the results of the synchronization analysis against the patient's progress over the ensuing 24 hours. These data will validate the ability to identify false and true labor using multichannel EMG and area sensors.

Inclusion Criteria:

• Pregnant
• One living fetus
• Experiencing frequent uterine contractions

Exclusion Criteria:

• Cervical dilation > 4 cm
• Ruptured membranes
• Maternal or fetal indications for immediate delivery

Subjects must be pregnant

Pregnant women with viable pregnancies who are experiencing uterine contractions will be studied. For each subject, her provider will not be certain if she is in true labor, or is experiencing false labor contractions. Other than experiencing contractions, subjects will have uncomplicated pregnancies. She will not have an indication for immediate delivery.

Specific patient EMG tracings may be shared based on unique characteristics of pregnancy subsets.