title: Water balance during parturition and early puerperium: A prospective open trial.
abstract: OBJECTIVE
  To investigate how water balance is regulated during labor and 27h postpartum.
  
  
  METHODS
  A prospective open trial with 49 women giving birth vaginally. Ringer-acetate was infused intravenously and combined with epidural analgesia in seven women (fluid group). Intravenous infusions of oxytocin in 5% glucose were given to 12 women (oxytocin group). Thirty women delivered their babies without infusion (nofluid group). Blood and urine samples were collected at arrival, at early stage 1, at early stage 2, and at aftercare, and 9, 15, and 27h postpartum. Plasma osmolality, sodium, cystatin C, vasopressin, oxytocin, urine flow, urine osmolality, and urine sodium were measued.
  
  
  RESULTS
  The oxytocin group had significantly lower plasma osmolality than the nofluid group before parturition, and they had lower plasma sodium concentration at early stage 1 and 2. Plasma vasopressin concentration was low and did not differ between groups or before and after parturition. Water diuresis developed postpartum in all groups. The cystatin C concentration decreased significantly after parturition in the oxytocin and nofluid groups.
  
  
  CONCLUSIONS
  The vasopressin levels were suppressed during parturition irrespective of the P-osmolality and the nongravid regulation of water balance had not returned within 27h postpartum.
authors.affiliation: Department of Health Sciences, Section of Health and Rehab, Luleå University of Technology, Luleå, Sweden.
authors.forename: Anitha
authors.initials: A
authors.lastname: Risberg
authors.affiliation: Swedish Centre for Animal Welfare, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Mats
authors.initials: M
authors.lastname: Sjöquist
authors.affiliation: Västerås Hospital, Västerås, Sweden.
authors.forename: Kai
authors.initials: K
authors.lastname: Wedenberg
authors.affiliation: Department of Economics, Unit of Applied Statistics and Mathematics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: Ulf
authors.initials: U
authors.lastname: Olsson
authors.affiliation: Department of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden. Electronic address: anders.larsson@akademiska.se.
authors.forename: Anders
authors.initials: A
authors.lastname: Larsson
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D055316:Cystatin C / Q000097:blood; D004573:Electrolytes / Q000097:blood; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D009994:Osmolar Concentration; D010121:Oxytocin / Q000494:pharmacology; D049590:Postpartum Period / Q000097:blood / Q000502:physiology*; D011247:Pregnancy; D011446:Prospective Studies; D012964:Sodium / Q000097:blood; D014554:Urination / Q000187:drug effects; D014882:Water-Electrolyte Balance / Q000187:drug effects
chemical_list: D055316:Cystatin C; D004573:Electrolytes; D010121:Oxytocin; D012964:Sodium
keywords: Osmolality; Oxytocin; Parturition; Puerperium; Vasopressin