title: How does the duration of active pushing in labor affect neonatal outcomes?
abstract: OBJECTIVE
  To assess the effect of time of active pushing (TAP) on neonatal outcome.
  
  
  METHODS
  The study population (n=36,432) was taken from a Swedish randomized control trial on intrapartum monitoring, a European Union fetal electrocardiogram trial, and from Mölndal Hospital. After validation of acid-base samples and TAP, 22,812 cases were accepted for analysis.
  
  
  RESULTS
  The median active TAP was 36 min for P0 and 13 min for P≥1 (P<0.001). After adjustments for parity, epidural, labor induction, birth weight, and gender, pushing for 15-29 min (n=6589) relative to pushing for <15 min (n=7264) increased the OR of a cord artery pH of <7.00 to 3.20 (95% CI 1.7-6.0), and that of a base deficit in extracellular fluid of >12 mmol/L to 3.5 (95% CI 1.3-9.0). The group with a cord artery pH of <7.00 had a longer TAP than the group with pH≥7.00: median (5th-95th percentile), 38 (9-107) min vs. 23 (5-87) min, P<0.001. The probability of a spontaneous vaginal delivery decreased significantly with every subsequent increase of 30 min in TAP (P<0.05).
  
  
  CONCLUSIONS
  The risks of severe acidemia, metabolic acidosis, and deteriorated neonatal outcome gradually increased with the length of TAP (>15 min), while the probability of a spontaneous vaginal delivery decreased with the duration of pushing. We suggest active physiological evaluation of the labor progress together with continuous electronic fetal monitoring during pushing irrespective of guideline thresholds.
authors.affiliation: Women and Children’s Division, Oslo University Hospital Rikshospitalet and Institute of Clinical Medicine, University of Oslo, Oslo, Norway. b.m.yli@medisin.uio.no
authors.forename: Branka M
authors.initials: BM
authors.lastname: Yli
authors.forename: Grete A Birkeland
authors.initials: GA
authors.lastname: Kro
authors.forename: Svein
authors.initials: S
authors.lastname: Rasmussen
authors.forename: Janette
authors.initials: J
authors.lastname: Khoury
authors.forename: Håkan
authors.initials: H
authors.lastname: Norèn
authors.forename: Isis
authors.initials: I
authors.lastname: Amer-Wåhlin
authors.forename: Ola Didrik
authors.initials: OD
authors.lastname: Saugstad
authors.forename: Babill
authors.initials: B
authors.lastname: Stray-Pedersen
mesh_terms: D000138:Acidosis / Q000453:epidemiology; D000328:Adult; D036861:Delivery, Obstetric; D005260:Female; D005312:Fetal Blood; D005323:Fetal Monitoring; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D007748:Labor Stage, Second / Q000502:physiology*; D008297:Male; D011247:Pregnancy; D011256:Pregnancy Outcome; D013997:Time Factors; D014469:Umbilical Arteries