title: Effect of pethidine administered during the first stage of labor on the acid-base status at birth.
abstract: OBJECTIVE
  To evaluate the association between the use of pethidine during the first stage of labor and the presence, type and timing of acidosis in the newborn at birth.
  
  
  METHODS
  Secondary data analysis of a randomized controlled trial, which included term singleton pregnancies diagnosed with dystocia and requiring active management of labor. Women were randomized to receive either 100 mg of pethidine or placebo. Statistical analyses were performed using chi(2) or Fisher's exact tests for proportions and multiple linear regression for continuous outcomes.
  
  
  RESULTS
  Three hundred and eighty-three pregnant women with a valid arterial blood cord sample were included in the final analysis. Lower pH and bicarbonate levels, as well as higher pCO(2) levels were found in the pethidide group. A higher incidence of acidosis was found in the pethidine group (pH<7.12 OR: 8.59 95% C.I. 3.29, 22.46). The highest frequency of acidosis was encountered when pethidine-delivery interval was 5 h.
  
  
  CONCLUSIONS
  Pethidine use during the first stage of labor was associated with an increased risk of acidosis at birth.
authors.affiliation: Department of Epidemiology, School of Public Health and Tropical Medicine, Tulane University, 1440 Canal Street, Ste. 1820, New Orleans, LA 70112, USA. csosa@tulane.edu
authors.forename: Claudio G
authors.initials: CG
authors.lastname: Sosa
authors.forename: Pierre
authors.initials: P
authors.lastname: Buekens
authors.forename: Janet M
authors.initials: JM
authors.lastname: Hughes
authors.forename: Erica
authors.initials: E
authors.lastname: Balaguer
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Sotero
authors.forename: Ruben
authors.initials: R
authors.lastname: Panizza
authors.forename: Hector
authors.initials: H
authors.lastname: Piriz
authors.forename: Justo G
authors.initials: JG
authors.lastname: Alonso
mesh_terms: D000136:Acid-Base Equilibrium / Q000187:drug effects*; D000138:Acidosis / Q000139:chemically induced*; D000701:Analgesics, Opioid / Q000009:adverse effects*; D005260:Female; D005312:Fetal Blood / Q000737:chemistry / Q000187:drug effects*; D006779:Hospitals, Public; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007231:Infant, Newborn; D048949:Labor Pain / Q000188:drug therapy*; D007747:Labor Stage, First; D008614:Meperidine / Q000009:adverse effects*; D011247:Pregnancy; D013997:Time Factors
chemical_list: D000701:Analgesics, Opioid; D008614:Meperidine