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INTRAUTERINE GROWTH RESTRICTION |
Obstet Gynecol. 2000 Nov;96(5 Pt 1):737-40.
Amniotic fluid index and single deepest pocket: weak indicators of abnormal
amniotic volumes.
Magann EF, Chauhan SP, Barrilleaux PS, Whitworth NS, Martin JN.
Department of Obstetrics and Gynecology, University of Mississippi Medical
Center, Jackson, Mississippi, USA.
Objectives:
To compare amniotic fluid index (AFI) with the single deepest
pocket in the identification of actual abnormal amniotic fluid (AF) volumes.
Methods:
One hundred seventy-nine women with singleton pregnancies at the
University of Mississippi between March 1994 and June 1999 had ultrasound
estimations of AF volume sequentially using the AFI and single deepest
pocket techniques. Each woman subsequently had ultrasound-directed
amniocentesis with dye-dilution and spectrophotometric calculation of actual
AF volume.
Results:
Actual AF volumes were low (under 5% by volume for
gestational age) in 62 women, normal (5-95%) in 100 women, and high (more
than 95%) in 17 women. An AFI up to 5 cm (sensitivity 10%, specificity 96%)
and a single deepest pocket up to 2 cm (sensitivity 5%, specificity 98%)
were similarly inadequate in identifying dye-determined low AF volumes.
Likewise, AFI above 20 (sensitivity 29%, specificity 97%) and a
single-deepest pocket above 8 cm (sensitivity 29%, specificity 94%) were
poor in identifying dye-determined abnormally high volumes.
Conclusion:
There was no difference between AFI and single deepest pocket techniques for
identifying truly abnormal AF volumes. Both techniques were unreliable for
identifying true AF volumes.
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