Trans-abdominal Fetal Pulse Oximetry

The Raydiant Oximetry Sensing System (Lumerah) is a non-invasive fetal pulse oximeter that measures fetal arterial oxygen saturation using safe, non-invasive, transabdominal near-infrared spectroscopy. Lumerah is intended as an adjunct to cardiotocography by detecting decreases in fetal oxygenation.

Raydiant Oximetry, Inc. is developing a novel and non-invasive fetal pulse oximetry device to fundamentally improve how fetuses are monitored during labor. The Raydiant Oximetry Sensing System (Lumerah) is a fetal pulse oximeter that measures fetal arterial oxygen saturation using safe, non-invasive, transabdominal near-infrared spectroscopy. Lumerah performs its measurements without the requirement for transvaginal placement and its associated risks. Lumerah is intended as an adjunct to cardiotocography by detecting fetal oxygen deprivation which is both life-threatening to the fetus and can lead to the irreversibly debilitating consequences of newborn metabolic acidosis. The severe consequences associated with newborn metabolic acidosis and the lack of availability of an effective tool to support its early diagnosis led to the development of Lumerah. In this study, women in labor will be simultaneously monitored with proven (previously FDA-approved) technology as a "ground truth". These women will be simultaneously monitored with both an external and internal oxygen sensor. Obstetric health-care providers are blinded to oximetry data presented by both devices; therefore, clinical decisions regarding interventions are made based on the standard factors, including cardiotocography. The primary efficacy analysis will be performed retrospectively by comparing data of fetal oxygenation displayed and recorded by both devices. Results of either the Lumerah external sensor or the internal sensor will not be used to guide or alter patient management.

This is a prospective, investigator-blinded study that is for data collection only. The primary purpose is to verify accuracy during the training of the algorithm by comparing the external sensor to a known internal sensor.

Results of either the external sensor or the internal sensor will not be shown to the subject, the care provider, or the investigator and will not be used to guide or alter patient management. The "outcomes assessor" will review the subject CTG and sensor data retrospectively.

The internal and external oxygen sensors will be used to record fetal oxygen during active labor and these will be be compared to the CTG retrospectively.

Rate of device-related adverse events such as erythema or rash on the maternal abdomen at the location of the sensor. Note: In this study, use of the device provides additional clinical information, but clinical judgement is based on standard fetal monitoring, including cardiotocography, and investigators are blinded to oximetry readings. The maternal skin at the sensor site will be examined intra and postpartum. Rate of device-related adverse events such as erythema or rash on the maternal abdomen at the location of the sensor.

Inclusion Criteria: Willing and capable to provide informed consent Age > 18 years BMI < 50 (with no more than 4 cm between maternal skin and fetal skin) Gestational age > 36 weeks Singleton pregnancy Vertex presentation Active labor Category I or Category II tracings Ruptured amniotic sac with cervical dilation of >2 cm and a station of -2 or lower Exclusion Criteria: Age <18 years BMI > 50 third trimester Gestational age < 36 weeks Multiple gestation Nonvertex fetal presentation Suspected vasa previa Latent labor Category III CTG tracing (i.e., need for immediate delivery) Fetal anomalies and/or chromosomal disorders Chorioamnionitis Placenta Previa History of HIV, Genital Herpes, or other infection precluding internal monitoring Unable to provide informed consent (e.g., cognitively impaired)