title: Maximal amniotic fluid index as a prognostic factor in pregnancies complicated by polyhydramnios.
abstract: OBJECTIVE
  Polyhydramnios is present in approximately 2% of pregnancies and has been associated with a variety of adverse pregnancy outcomes. Our aim was to evaluate the association between the maximal amniotic fluid index (AFI) and the frequency of specific adverse outcomes.
  
  
  METHODS
  This was a retrospective chart review of 524 singleton pregnancies diagnosed with polyhydramnios and delivered in a single tertiary referral center between 2003 and 2008. Polyhydramnios was defined as either AFI ≥ 25 cm or a maximum vertical pocket (MVP) ≥ 8 cm even in the presence of AFI < 25 cm. The cohort was stratified into four groups based on the maximal AFI noted during the pregnancy: < 25 cm but with MVP ≥ 8 cm; 25-29.9 cm; 30-34.9 cm; and ≥ 35 cm. Data were collected to determine the frequency of the following adverse pregnancy outcomes: prenatally diagnosed congenital anomalies, fetal aneuploidy, preterm delivery, Cesarean delivery, low birth weight, 5-min Apgar score < 7 and perinatal mortality.
  
  
  RESULTS
  Higher AFI was associated with a statistically significant increase in the frequency of adverse pregnancy outcomes. The most severe form of polyhydramnios, as based on the maximal AFI (≥ 35 cm; n = 67), was associated with the highest rates of prenatally diagnosed congenital anomalies (79%), preterm delivery (46%), small-for-gestational-age neonate (16%), aneuploidy (13%) and perinatal mortality (27%). No significant association between degree of polyhydramnios and adverse outcome was demonstrated in cases of idiopathic polyhydramnios (n = 253).
  
  
  CONCLUSIONS
  There is an association between the frequencies of a variety of adverse pregnancy outcomes and the severity of polyhydramnios as reflected by the maximal AFI.
authors: Division of Maternal Fetal Medicine, Department of Obstetrics and Gynecology, Columbia University Medical Center, New York, New York 10032, USA. smp9009@med.cornell.edu
authors: S
authors: S
authors: Pri-Paz
authors: N
authors: N
authors: Khalek
authors: K M
authors: KM
authors: Fuchs
authors: L L
authors: LL
authors: Simpson
mesh_terms: D000293:Adolescent; D000328:Adult; D000653:Amniotic Fluid; D000704:Analysis of Variance; D002585:Cesarean Section; D002887:Chromosomes, Human, Pair 18; D015331:Cohort Studies; D004314:Down Syndrome / Q000175:diagnosis* / Q000401:mortality / Q000473:pathology; D005260:Female; D005313:Fetal Death; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008499:Medical Records; D008875:Middle Aged; D006831:Polyhydramnios / Q000175:diagnosis* / Q000401:mortality; D011247:Pregnancy; D011256:Pregnancy Outcome; D047928:Premature Birth; D011379:Prognosis; D012189:Retrospective Studies; D014314:Trisomy / Q000175:diagnosis*; D055815:Young Adult