Table 4 Duration of pushing in vaginal deliveries and risks of umbilical artery acidosis, birth asphyxia-related complications and admission to NICU

From: Durations of second stage of labor and pushing, and adverse neonatal outcomes: a population-based cohort study

  Acidosisa (N=339) Birth asphyxia-related complicationsb (N=250) Admission NICU (N=2577)
  N totalc % aRR d (95% CI) N total % aRR d (95% CI) % aRR d (95% CI)
  32 417 1.05    41 340 0.60    6.23   
Pushing (min)
 0 to <15 3520 0.57 1.00 Reference 4565 0.42 1.00 Reference 5.39 1.00 Reference
 15 to <30 9949 0.81 1.41 (0.86–2.34) 12 820 0.46 1.07 (0.64–1.80) 4.90 0.94 (0.81–1.09)
 30 to <45 8082 1.03 1.80 (1.09–2.98) 10 126 0.49 1.03 (0.60–1.76) 5.93 1.11 (0.96–1.29)
 45 to <60 4701 1.15 1.93 (1.13–3.28) 5943 0.81 1.65 (0.95–2.85) 7.47 1.43 (1.22–1.67)
60 4208 1.69 2.55 (1.51–4.30) 5338 0.73 1.60 (0.91–2.81) 7.96 1.54 (1.31–1.80)
 Missing 1957 1.53    2548 1.37    9.18   
  1. Abbreviations: BE, base excess; BMI, body mass index; HIE, hypoxic ischemic encephalopathy; MAS, meconium aspiration syndrome; NICU, neonatal intensive care unit.
  2. aAcidosis: umbilical artery acidosis, pH<7.05 and BE< −12.
  3. bBirth asphyxia-related complications include any of the following conditions: HIE, hypothermia treatment, neonatal seizures, MAS or advanced resuscitation after birth (heart compressions or intubation).
  4. cMissing data on pH and/or BE: N=8923.
  5. dAdjusted for maternal characteristics: maternal age, height, BMI, smoking, hypertensive disease and diabetes. Delivery and fetal characteristics: onset of delivery (spontaneous or induction), oxytocin before pushing phase, duration of second stage before pushing phase and gestational length at birth.