title: A diminished intrapartum amniotic fluid index is a predictive marker of possible adverse neonatal outcome when associated with prolonged labor.
abstract: OBJECTIVE
  To determine whether a diminished intrapartum amniotic fluid volume represents a risk of adverse neonatal outcome when it occurs in conjunction with prolonged labor.
  
  
  METHODS
  The intrapartum amniotic fluid index (iAFI) was measured in 242 parturients over 35 weeks of gestation during 1st-stage labor, and the umbilical artery blood gas was analyzed at delivery. The subjects were divided into group A (n = 99), having a diminished amniotic fluid volume (iAFI < or = 8.0 cm) and group B (n = 143), having a normal amniotic fluid volume (iAFI 8.1-20.0 cm), and selected antenatal, delivery, and neonatal variables were compared. In addition, the two groups were subdivided according to the duration of labor. Statistical analysis was performed using independent Student's t test, Mann-Whitney U test, chi-square analysis, and Fisher's exact test where appropriate. p < 0.05 was considered significant.
  
  
  RESULTS
  The patient characteristics and pregnancy outcomes were similar in groups A and B, as were the incidences of an umbilical artery blood pH <7.20 and/or an Apgar score <7 (group A 9.5%, group B 10.1%). In group A, however, the incidence of an adverse neonatal outcome was 23.5% in cases in whom the duration of labor was longer than 8 h which was significantly higher than in cases in whom the duration of labor was 8 h or less (2.8%; p < 0.01). In group B, the incidence of an adverse neonatal outcome was similar in the two subgroups.
  
  
  CONCLUSIONS
  The risk of an adverse neonatal outcome is higher in patients with diminished amniotic fluid volume if labor is prolonged. Consequently, determination of the iAFI could be a useful admission test.
authors.affiliation: Department of Obstetrics and Gynecology, Shimonoseki Kosei Hospital, Japan. nori-kawasaki@hkg.odn.ne.jp
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Kawasaki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nishimura
authors.forename: Toshiro
authors.initials: T
authors.lastname: Yoshimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Okamura
mesh_terms: D000328:Adult; D000653:Amniotic Fluid; D001034:Apgar Score; D005260:Female; D005312:Fetal Blood; D006801:Humans; D007747:Labor Stage, First; D007743:Labor, Obstetric; D007744:Obstetric Labor Complications; D011247:Pregnancy; D011256:Pregnancy Outcome; D012306:Risk; D013997:Time Factors; D016216:Ultrasonography, Prenatal