title: Relationship between change in amniotic fluid index and volume of fluid removed at amnioreduction.
abstract: OBJECTIVE
  To determine the relationship between the change in amniotic fluid index (AFI) and the volume of fluid removed at amnioreduction.
  
  
  METHODS
  In a prospective study of 20 twin and 19 singleton pregnancies undergoing amnioreduction for severe polyhydramnios, AFI was measured immediately before and after the procedure and was correlated with the volume of fluid withdrawn.
  
  
  RESULTS
  A significant linear relationship was found between AFI change and the volume drained in all pregnancies (Y = -4.2X; R2 = 0.49; P = .002). This relationship was similar in singleton and twin pregnancies. However, there was a significant absolute difference in AFI change between singleton and twin pregnancies of 7.9 cm (95% confidence interval 0.41, 15.2; P = .04).
  
  
  CONCLUSIONS
  These findings support the use of the four-quadrant AFI as a semiquantitative index of amniotic fluid volume. This relationship can be used to predict the drainage volume required to achieve a target AFI with amnioreduction and thus avoid repeated AFI measurements during the procedure itself.
authors.affiliation: Institute of Obstetrics and Gynaecology, Royal Postgraduate Medical School, Queen Charlotte's and Chelsea Hospital, London, United Kingdom.
authors.forename: M L
authors.initials: ML
authors.lastname: Denbow
authors.forename: W
authors.initials: W
authors.lastname: Sepulveda
authors.forename: D
authors.initials: D
authors.lastname: Ridout
authors.forename: N M
authors.initials: NM
authors.lastname: Fisk
mesh_terms: D000328:Adult; D000653:Amniotic Fluid; D005260:Female; D006801:Humans; D006831:Polyhydramnios / Q000628:therapy*; D011247:Pregnancy; D011446:Prospective Studies; D012720:Severity of Illness Index