Longitudinal growth assessment for prediction of adverse perinatal outcome in fetuses suspected to be small-for-gestational age.

Objective: Fetal growth restriction (FGR) is associated with an increased risk of adverse perinatal outcome. However, distinguishing this condition from small-for-gestational age (SGA) remains elusive. A set of criteria has been proposed recently for such a purpose, including the degree of smallness, Doppler parameters and growth velocity. The aim of this study was to establish whether the use of growth velocity adds value to Doppler assessment in predicting adverse perinatal outcome among SGA-suspected fetuses.

Methods: This was a prospective cohort study of consecutive singleton pregnancies with late (diagnosis ≥ 32.0 weeks) SGA (estimated fetal weight (EFW) < 10 centile). Longitudinal growth assessment was performed by calculation of EFW z-velocity between diagnosis and last scan before delivery. Improvement in the association with and predictive performance of EFW z-velocity for adverse perinatal outcome was compared against standard criteria of FGR evaluated before delivery (EFW < 3 centile, abnormal uterine Doppler or abnormal cerebroplacental ratio).

Result: A total of 472 patients were evaluated prospectively for suspected SGA. Of these, 231 (48.9%) qualified as late FGR. Univariate analysis showed a significant trend towards higher frequency (14.5% vs 8.2%; P = 0.041) of EFW z-velocity in the lowest decile in pregnancies with adverse perinatal outcome. Nonetheless, the addition of EFW z-velocity improved neither the association with nor the predictive performance of standard criteria of FGR for adverse perinatal outcome.

Conclusions: Longitudinal assessment of fetal growth by means of EFW z-velocity did not have any independent predictive value for adverse perinatal outcome when used in combination with Doppler in SGA-suspected fetuses. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.