Electrode-Based Sensor for Non-Invasive Fetal Heart Rate Monitoring With Improved Reliability

Completed

Conditions: Laboring Women With Ultrasound and FSE Monitoring

Registration Number: NCT02024165

Lead Sponsor: OBMedical Company

Brief Summary: 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.

Detailed Description: 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.

Maternal obesity (defined as BMI at presentation ≥ 30) is an ever-increasing problem in the US, and is even more prominent in the obstetric suite. Meanwhile, obese women have an increased risk for labor problems, infections and other complications. Noninvasive labor monitoring, while preferable to reduce the infection risk, is particularly unreliable in this population.

Recruitment & Eligibility

Status: COMPLETED

Sex: Female

Target Recruitment: 71

Inclusion Criteria

Parturients presenting to Labor & Delivery for labor at term (>36 weeks completed gestation)
Single viable fetus in cephalic presentation
With FSE or IUPC for obstetric indications

Exclusion Criteria

Multi fetal gestation
Contraindication to FSE or IUPC placement
Insufficient abdominal space for all required sensors

Study & Design

Study Type: OBSERVATIONAL

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Fetal Heart Rate Interpretability	2 hours	The Fetal Heart Rate (or FHR) of the electrode sensor will be compared to the FHR of the ultrasound when both are compared to the FSE. Percentage of time that signals are interpretable will be compared between devices

Secondary Outcome Measures