title: Oxytocin administered during labor and breast-feeding: a retrospective cohort study.
abstract: OBJECTIVE
  The relationship between labor physiology and the onset of lactation leads to assess the potential correlation between oxytocin administration during labor and duration of breast-feeding.
  
  
  METHODS
  This study was designed as a retrospective cohort study where patients given synthetic oxytocin during labor induction were considered as the exposed cohort, and patients not given oxytocin formed the non-exposed cohort. Four hundred of the 7465 children born at our maternity during 2006 were randomly selected. Information about breast-feeding was available for 316 of these children. Eventual confounding or adjustment factors were analyzed using stratified and multivariate analysis.
  
  
  RESULTS
  Oxytocin was used for delivery of 189 (59.8%) newborns, multiplying the risk of bottle-feeding by 1.451 (95% CI 1.28-1.63). The best-fit regression model of oxytocin use effect on bottle-feeding included sex and gestational age of the newborn. The use of oxytocin also multiplies the risk of breast-feeding withdrawal at 3 months by 2.29 (95% CI 1.41-3.74). This effect is confounded by maternal age, being higher for mothers under 27 years.
  
  
  CONCLUSIONS
  Oxytocin administration during labor had some impact on both onset and duration of breast-feeding, particularly in mothers under 27 years of age and newborns delivered at term. Clinical Study registered at U.S.
  NCT01951040.
authors.affiliation: Obstetric and Gynecology Research Group at Malaga Regional and University Hospital (IBIMA) , Málaga , Spain and.
authors.forename: Pedro
authors.initials: P
authors.lastname: García-Fortea
authors.forename: Ernesto
authors.initials: E
authors.lastname: González-Mesa
authors.forename: Marta
authors.initials: M
authors.lastname: Blasco
authors.forename: Olga
authors.initials: O
authors.lastname: Cazorla
authors.forename: M
authors.initials: M
authors.lastname: Delgado-Ríos
authors.forename: María J
authors.initials: MJ
authors.lastname: González-Valenzuela
mesh_terms: D000328:Adult; D001942:Breast Feeding / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007747:Labor Stage, First; D007748:Labor Stage, Second; D007751:Labor, Induced / Q000009:adverse effects*; D010120:Oxytocics / Q000008:administration & dosage / Q000009:adverse effects*; D010121:Oxytocin / Q000008:administration & dosage / Q000009:adverse effects*; D011247:Pregnancy; D012189:Retrospective Studies
chemical_list: D010120:Oxytocics; D010121:Oxytocin
keywords: Bottle feeding; breast-feeding; cohort study; labor; oxytocin