The MFMU network randomized trial of fetal pulse oximetry

Abstract

ObjectiveTo measure whether knowledge of fetal oxygen saturation, as an adjunct to continuous electronic fetal monitoring, (1) is associated with a significant change in the overall rate of cesarean delivery, including those performed specifically for non-reassuring fetal heart rate pattern and dystocia, and (2) is related to infant condition at birth.Study design5341 nulliparous women at term in early labor were randomly assigned to “open” or “masked” fetal pulse oximetry. In the “open” arm, fetal oxygen saturation values were displayed to the clinician. In the “masked” group, the fetal oxygen sensor was inserted and the values recorded by computer, but the data were hidden. Labors complicated by a non-reassuring fetal heart rate pattern prior to randomization were documented for subsequent analysis. The trial was stopped before the final sample size of 10,000 because the overall cesarean rate (primary outcome) in the masked arm was higher than expected, and there was >90% power to detect the prespecified 15% reduction in the open arm.ResultsTabled 1Outcome“Open” arm n = 2,629“Masked” arm n = 2,712P-valueCesarean Rate-Overall26.3%27.5%0.31Indication: Non-Reassuring FHR7.1%7.9%0.30 Dystocia18.6%19.2%0.59Forceps/Vacuum14.5%14.7%0.765-Minute Apgar: 7 or less2.9%3.2%0.55 3 or less0.2%0.1%0.34Newborn Seizures0.1%0.2%0.51HIE00.04%1.0Intrapartum Stillbirth00—Neonatal Death00.04%1.0 Open table in a new tab ConclusionKnowledge of fetal oxygen saturation is not associated with a reduction in the rate of cesarean delivery or improvement in newborn condition. ObjectiveTo measure whether knowledge of fetal oxygen saturation, as an adjunct to continuous electronic fetal monitoring, (1) is associated with a significant change in the overall rate of cesarean delivery, including those performed specifically for non-reassuring fetal heart rate pattern and dystocia, and (2) is related to infant condition at birth. To measure whether knowledge of fetal oxygen saturation, as an adjunct to continuous electronic fetal monitoring, (1) is associated with a significant change in the overall rate of cesarean delivery, including those performed specifically for non-reassuring fetal heart rate pattern and dystocia, and (2) is related to infant condition at birth. Study design5341 nulliparous women at term in early labor were randomly assigned to “open” or “masked” fetal pulse oximetry. In the “open” arm, fetal oxygen saturation values were displayed to the clinician. In the “masked” group, the fetal oxygen sensor was inserted and the values recorded by computer, but the data were hidden. Labors complicated by a non-reassuring fetal heart rate pattern prior to randomization were documented for subsequent analysis. The trial was stopped before the final sample size of 10,000 because the overall cesarean rate (primary outcome) in the masked arm was higher than expected, and there was >90% power to detect the prespecified 15% reduction in the open arm. 5341 nulliparous women at term in early labor were randomly assigned to “open” or “masked” fetal pulse oximetry. In the “open” arm, fetal oxygen saturation values were displayed to the clinician. In the “masked” group, the fetal oxygen sensor was inserted and the values recorded by computer, but the data were hidden. Labors complicated by a non-reassuring fetal heart rate pattern prior to randomization were documented for subsequent analysis. The trial was stopped before the final sample size of 10,000 because the overall cesarean rate (primary outcome) in the masked arm was higher than expected, and there was >90% power to detect the prespecified 15% reduction in the open arm. ResultsTabled 1Outcome“Open” arm n = 2,629“Masked” arm n = 2,712P-valueCesarean Rate-Overall26.3%27.5%0.31Indication: Non-Reassuring FHR7.1%7.9%0.30 Dystocia18.6%19.2%0.59Forceps/Vacuum14.5%14.7%0.765-Minute Apgar: 7 or less2.9%3.2%0.55 3 or less0.2%0.1%0.34Newborn Seizures0.1%0.2%0.51HIE00.04%1.0Intrapartum Stillbirth00—Neonatal Death00.04%1.0 Open table in a new tab ConclusionKnowledge of fetal oxygen saturation is not associated with a reduction in the rate of cesarean delivery or improvement in newborn condition. Knowledge of fetal oxygen saturation is not associated with a reduction in the rate of cesarean delivery or improvement in newborn condition.