Normal resting tone N=1643 Elevateda resting tone 30 min prior to delivery N=333 Persistent elevated resting tone 120 min prior to delivery N=234 aOR (95% CI)b Normal vs 30min
aOR (95% CI)b Normal vs 120min
P for trend
Composite neonatal morbidityc 48(2.9) 13 (3.9) 16 (6.8) 1.34 (0.71-2.50) 2.21 (1.22-4.01) 0.03
NICU admissiond 14 (0.9) 4 (1.2) 5 (2.1) 1.39 (0.45-4.26) 2.33 (0.82-6.62) 0.28
5-minute Apgar Score <7 26 (1.6) 4 (1.2) 12 (5.1) 0.74 (0.26-2.15) 3.14 (1.55-6.37) <0.01
Umbilical artery
pH <7.2 165 (10.2) 56 (16.8) 41 (17.5) 1.79 (1.29-2.48) 1.84 (1.26-2.67) <0.01
Lactate ≥ 4 mmol/l 382 (23.7) 93 (28.0) 85 (36.3) 1.25 (0.96-1.63) 1.78 (1.33-2.39) <0.01
aElevated tone defined as > 75th percentile bAdjusted for chorioamnionitis, amnioinfusion cComposite Neonatal Morbidity: Hypoxic Ischemic encephalopathy, hypothermia treatment, intubation, seizures, UA pH≤7.1, oxygen requirement, and neonatal death dNeonatal intensive care admission aElevated tone defined as > 75th percentile bAdjusted for chorioamnionitis, amnioinfusion cComposite Neonatal Morbidity: Hypoxic Ischemic encephalopathy, hypothermia treatment, intubation, seizures, UA pH≤7.1, oxygen requirement, and neonatal death dNeonatal intensive care admission aElevated tone defined as > 75th percentile bAdjusted for chorioamnionitis, amnioinfusion cComposite Neonatal Morbidity: Hypoxic Ischemic encephalopathy, hypothermia treatment, intubation, seizures, UA pH≤7.1, oxygen requirement, and neonatal death dNeonatal intensive care admission aElevated tone defined as > 75th percentile bAdjusted for chorioamnionitis, amnioinfusion cComposite Neonatal Morbidity: Hypoxic Ischemic encephalopathy, hypothermia treatment, intubation, seizures, UA pH≤7.1, oxygen requirement, and neonatal death dNeonatal intensive care admission aElevated tone defined as > 75th percentile bAdjusted for chorioamnionitis, amnioinfusion cComposite Neonatal Morbidity: Hypoxic Ischemic encephalopathy, hypothermia treatment, intubation, seizures, UA pH≤7.1, oxygen requirement, and neonatal death dNeonatal intensive care admission aElevated tone defined as > 75th percentile bAdjusted for chorioamnionitis, amnioinfusion cComposite Neonatal Morbidity: Hypoxic Ischemic encephalopathy, hypothermia treatment, intubation, seizures, UA pH≤7.1, oxygen requirement, and neonatal death dNeonatal intensive care admission aElevated tone defined as > 75th percentile bAdjusted for chorioamnionitis, amnioinfusion cComposite Neonatal Morbidity: Hypoxic Ischemic encephalopathy, hypothermia treatment, intubation, seizures, UA pH≤7.1, oxygen requirement, and neonatal death dNeonatal intensive care admission