Second-trimester prediction of delivery of a small-for-gestational-age neonate: integrating sequential Doppler information, fetal biometry, and maternal characteristics

ObjectiveThe aim of this study was to investigate the predictive accuracy of second-trimester ultrasound parameters, maternal characteristics, and sequential Doppler changes between first and second trimesters for the prediction of small-for-gestational-age (SGA) infants (birth weight<10th percentile). MethodsWe conducted a prospective study of singleton pregnancies enrolled in the first trimester with subsequent second-trimester follow-up. Maternal characteristics, uterine artery (UtA) pulsatility index (PI), fetal biometry, and umbilical artery (UA)-PI were ascertained. UtA and UA-PI change from first to second trimester was calculated (UtA-PI and UA-PI). These parameters were tested for their ability to predict delivery of an SGA infant. ResultsAmong 1982 women, 172 delivered an SGA neonate. African-American ethnicity, nulliparity, tobacco use, and low abdominal circumference (AC) z-score were independent predictors of SGA. No difference was found in the magnitude of UtA-PI and UA-PI between SGA and no-SGA. Receiver-operating characteristics curve analysis yielded an area under the curve of 0.700 for AC z-score. The combination of low AC and bilateral notching had high specificity (99%) but low sensitivity (7%) for SGA prediction. ConclusionsA small second-trimester fetal AC is a specific marker for SGA when found with bilateral UtA notching. Only a small proportion is predicted by the factors studied, suggesting a small contributory role or later evolution of SGA. (c) 2014 John Wiley & Sons, Ltd.