title: Active pushing versus passive fetal descent in the second stage of labor: a randomized controlled trial.
abstract: OBJECTIVE
  To compare perinatal outcomes among women with epidural anesthesia who were encouraged to push at complete dilatation with those who had a period of rest before pushing began.
  
  
  METHODS
  After a power analysis to determine appropriate sample size (based upon an alpha error rate of.05% and 80% power), a prospective randomized trial of 252 women with epidural anesthesia was conducted. Patients were randomized to a rest period or immediate pushing at complete dilatation. Variables measured included rate of fetal descent, length of time of pushing, the number and type of fetal heart rate decelerations, Apgar scores, arterial cord pH values, perineal injuries, type of delivery, length of second stage, maternal fatigue, and endometritis.
  
  
  RESULTS
  When a period of rest was used before pushing, we found a longer second stage, decreased pushing time, fewer decelerations, and, in primiparous women, less fatigue compared with control patients. Apgar scores, arterial cord pH values, rates of perineal injury, instrument delivery, and endometritis were similar in both groups.
  
  
  CONCLUSIONS
  Delayed pushing was not associated with demonstrable adverse outcome, despite second-stage length of up to 4.9 hours. In select patients, such delay may be of benefit.
authors.affiliation: Intermountain Health Care, Salt Lake City, Utah, USA.
authors.forename: Susan L
authors.initials: SL
authors.lastname: Hansen
authors.forename: Steven L
authors.initials: SL
authors.lastname: Clark
authors.forename: Joyce C
authors.initials: JC
authors.lastname: Foster
mesh_terms: D000328:Adult; D000767:Anesthesia, Epidural; D000773:Anesthesia, Obstetrical; D001034:Apgar Score; D020070:Cervical Ripening; D036861:Delivery, Obstetric / Q000379:methods*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007748:Labor Stage, Second / Q000502:physiology*; D011247:Pregnancy; D011336:Probability; D011446:Prospective Studies; D012016:Reference Values; D012680:Sensitivity and Specificity; D013997:Time Factors