Prediction of small for gestational age newborns using ultrasound estimated and actual amniotic fluid volume: published data revisited.
BACKGROUND
Intrauterine growth restriction (IUGR) is a complex problem in modern obstetrics. The presence of oligohydramnios is reported as an important diagnostic and prognostic factor in the management of a pregnancy complicated by IUGR.


OBJECTIVE
To determine the predictive accuracy of sonographic and actual amniotic fluid volume (AFV) to identify small for gestational age (SGA; birthweight < 10%).


METHODS
Before amniocentesis, the single deepest pocket (SDP) and amniotic fluid index (AFI) were obtained. The AFV was determined using a diazo-dye reaction. Thresholds for AFI, SDP and AFV were estimated using receiver-operating curves analysis and areas under the curves were used to assess predictive accuracy of these indices. Likelihood ratios (LR) were obtained.


RESULTS
Among the 175 newborns, 16% had SGA. Compared to newborns with birthweight > 10%, all AFV indices were significantly lower (P= 0.001, P= 0.001 and P= 0.009 for AFI, SDP and AFV respectively) for SGA. The areas under the curves for all curves < 0.65 and the LR for all thresholds were < 5.0, reflecting poor diagnostic capabilities.


CONCLUSIONS
Despite observed lower AFV indices in SGA, neither sonographic examination nor determination of AFV is a reliable predictor of suboptimal growth.
Chauhan
Suneet P
SP
Departments of Obstetrics and Gynaecology, Aurora Health Care, West Allis, Wisconsin, USA.
Magann
Everett F
EF
Dohrety
Dorota A
DA
Ennen
Christopher S
CS
Niederhauser
Amy
A
Morrison
John C
JC
D000328:Adult; D000653:Amniotic Fluid; D001724:Birth Weight; D005260:Female; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D016104:Oligohydramnios / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011247:Pregnancy; D012372:ROC Curve; D012189:Retrospective Studies; D016216:Ultrasonography, Prenatal