title: An Update on Maternal Hydration Strategies for Amniotic Fluid Improvement in Isolated Oligohydramnios and Normohydramnios: Evidence from a Systematic Review of Literature and Meta-Analysis.
abstract: OBJECTIVE
  Several trials aimed at evaluating the efficacy of maternal hydration (MH) in increasing amniotic-fluid-volume (AFV) in pregnancies with isolated oligohydramnios or normohydramnos have been conducted. Unfortunately, no evidences support this intervention in routine-clinical-practice. The aim of this systematic-literature-review and meta-analysis was to collect all data regarding proposed strategies and their efficacy in relation to each clinical condition for which MH-therapy was performed with the aim of increasing amniotic-fluid (AF) and improving perinatal outcomes.
  
  
  METHODS
  A systematic literature search was conducted in electronic-database MEDLINE, EMBASE, ScienceDirect and the Cochrane-Library in the time interval between 1991 and 2014. Following the identification of eligible trials, we estimated the methodological quality of each study (using QADAS-2) and clustered patients according to the following outcome measures: route of administration (oral versus intravenous versus combined), total daily dose of fluids administered (<2000 versus >2000), duration of hydration therapy: (1 day, >1 day but <1 week, >1 week), type of fluid administered (isotonic versus hypotonic versus combination).
  
  
  RESULTS
  In isolated-oligohydramnios (IO), maternal oral hydration is more effective than intravenous hydration and hypotonic solutions superior to isotonic solutions. The improvement in AFV appears to be time-dependent rather than daily-dose dependent. Regarding normohydramnios pregnancies, all strategies seem equivalent though the administration of hypotonic-fluid appears to have a slightly greater effect than isotonic-fluid. Regarding perinatal outcomes, data is fragmentary and heterogeneous and does not allow us to define the real clinical utility of MH.
  
  
  CONCLUSIONS
  Available data suggests that MH may be a safe, well-tolerated and useful strategy to improve AFV especially in cases of IO. In view of the numerous obstetric situations in which a reduced AFV may pose a threat, particularly to the fetus, the possibility of increasing AFV with a simple and inexpensive practice like MH-therapy may have potential clinical applications. Considering the various strategies of maternal hydration implemented in the treatment of IO, better results were observed when treatment was based on a combination of intravenous (for a period of 1 day) and oral (for a period of at least 14 days) hypotonic fluids (≥2000ml).
authors.affiliation: Department of Woman and Child Health - University of Padua, Padua, Italy.|Department of Obstetrics and Gynecology - NHS Trust - Northampton General Hospital- Northampton, United Kingdom.
authors.forename: Salvatore
authors.initials: S
authors.lastname: Gizzo
authors.affiliation: Department of Woman and Child Health - University of Padua, Padua, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Noventa
authors.affiliation: Department of Woman and Child Health - University of Padua, Padua, Italy.
authors.forename: Amerigo
authors.initials: A
authors.lastname: Vitagliano
authors.affiliation: Department of Surgical Sciences - University of Parma, Parma, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Dall'Asta
authors.affiliation: Department of Woman and Child Health - University of Padua, Padua, Italy.
authors.forename: Donato
authors.initials: D
authors.lastname: D'Antona
authors.affiliation: Department of Obstetrics and Gynecology - NHS Trust - Northampton General Hospital- Northampton, United Kingdom.
authors.forename: Clive J
authors.initials: CJ
authors.lastname: Aldrich
authors.affiliation: Department of Obstetrics and Gynaecology, University of Verona, Verona, Italy.
authors.forename: Michela
authors.initials: M
authors.lastname: Quaranta
authors.affiliation: Department of Surgical Sciences - University of Parma, Parma, Italy.
authors.forename: Tiziana
authors.initials: T
authors.lastname: Frusca
authors.affiliation: Department of Surgical Sciences - University of Parma, Parma, Italy.|Vicenza General Hospital, Vicenza, Italy.
authors.forename: Tito Silvio
authors.initials: TS
authors.lastname: Patrelli
mesh_terms: D061605:Administration, Intravenous; D000284:Administration, Oral; D000653:Amniotic Fluid / Q000378:metabolism*; D002986:Clinical Trials as Topic; D005260:Female; D005440:Fluid Therapy; D006801:Humans; D007038:Hypotonic Solutions / Q000008:administration & dosage; D007552:Isotonic Solutions / Q000008:administration & dosage; D016104:Oligohydramnios / Q000628:therapy*; D011247:Pregnancy
chemical_list: D007038:Hypotonic Solutions; D007552:Isotonic Solutions