The specific goal of the proposed research is to develop a reliable, non-invasive fetal and maternal heart rate and contraction monitor that is unaffected by obesity and requires less nursing intervention than the tocodynamometer and Doppler ultrasound.

The majority of obstetric deliveries in the US undergo electronic monitoring and continuous uterine activity and fetal heart rate (FHR) monitoring is the standard of care. Typically, external transducers are employed, the reliability of which depends on their proper positioning, which may be disturbed by patient or fetal movement. The tocodynamometer (strain gauge, toco for short) provides frequency and timing of contractions, but requires transmission of tension from the uterus to the sensor. Fetal heart rate is acquired with an external Doppler ultrasound transducer. The reliability of this monitor depends on the ability to obtain a window to the fetal heart.

In some patients, particularly the obese, the toco and ultrasound may fail to monitor consistently. In others both transducers require frequent repositioning by the nursing staff, and the Doppler may erroneously report maternal heart rate instead of fetal.

The alternative uterine activity monitor is an intrauterine pressure catheter (IUPC), which is placed through the cervical os in the adequately dilated patient with ruptured membranes. While this monitor usually provides a more reliable signal than the toco, as well as quantitative information regarding intrauterine pressure, it is invasive and there is an increased risk of infection. The alternative FHR monitor is via fetal scalp electrode (FSE), which is applied transvaginally to the fetal presenting part, also requiring adequate cervical dilation and ruptured membranes. While the FSE usually provides a more reliable signal, it is similarly invasive and increases risk of infection.

Inclusion Criteria:

• Women between the ages of 18 and 50 years old
• >/= 34 weeks gestation
• Single viable fetus in cephalic presentation

Exclusion Criteria:

• Bleeding or uterine scarring

The number of participants was determined by the time allowable by the IRB approval for the site study.

Adverse events occurred throughout the study dates starting 8/1/11 and ending 4/25/13. 1 year 9 months.

All adverse events were recorded, even if the event was not directly related to the study. Some patients developed infection directly after data collection started and thus were already infected, not being caused by the study. Also, C-sections were reported as it disrupted the data collection and was not a foreseeable event.