Doppler US in the Evaluation of Fetal Growth and Perinatal Health.

Fetal growth restriction is commonly defined as an estimated fetal weight (EFW) that is below the 10th percentile for gestational age. It is associated with an increased risk of intrauterine demise, neonatal morbidity, and neonatal death; therefore, antenatal detection and surveillance with the optimization of delivery timing are necessary to improve pregnancy outcomes. If the estimated due date has been verified and the EFW is below the 10th percentile for gestational age, the underlying cause should be investigated, since the clinical management, outcome, and counseling options are largely dependent on the cause of the growth restriction. Serial ultrasonography (US) for the evaluation of fetal growth and umbilical artery Doppler velocimetry are used to guide pregnancy management decisions. This article describes the accurate US detection and surveillance of fetal growth restriction, discusses the current obstetric and radiology literature regarding the use of Doppler velocimetry in the setting of fetal growth restriction, and describes the techniques for performing umbilical artery Doppler velocimetry. Although various Doppler techniques have been described in the setting of fetal growth restriction, only umbilical artery Doppler assessment is recommended to identify fetuses most at risk for poor outcome and to guide the timing of delivery. The use of other Doppler waveforms in this setting remains investigational. RSNA, 2017.