Prediction of delivery of small‐for‐gestational‐age neonates and adverse perinatal outcome by fetoplacental Doppler at 37 weeks' gestation

• Published in: Ultrasound in obstetrics & gynecology Vol. 49; no. 3; pp. 364 - 371
• Main Authors: Triunfo, S., Crispi, F., Gratacos, E., Figueras, F.
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01-03-2017; Wiley Subscription Services, Inc
• Subjects: Acidosis; adverse perinatal outcome; Apgar score; Birth weight; Blood flow; cerebroplacental ratio; Cesarean section; Doppler; Female; fetal growth restriction; Fetal Growth Retardation - diagnostic imaging; Fetal Weight; Fetuses; Gestation; Humans; Infant, Newborn; Infant, Small for Gestational Age; Neonates; Newborn babies; Predictions; Predictive Value of Tests; Pregnancy; Pregnancy Trimester, Third; Prospective Studies; Ultrasonic imaging; ultrasonography; Ultrasonography, Doppler - methods; Ultrasonography, Prenatal - methods; Umbilical vein; umbilical vein blood flow; uterine artery; Uterus; umbilical vein blood flow; fetal growth restriction; uterine artery; cerebroplacental ratio; ultrasonography; Doppler; adverse perinatal outcome
• ISSN: 0960-7692; 1469-0705
• DOI: 10.1002/uog.15979

ABSTRACT
Objective
To explore the predictive capacity of fetoplacental Doppler at 37 weeks' gestation in identifying small‐for‐gestational‐age (SGA) neonates, fetal growth restriction (FGR) and adverse perinatal outcome.
Methods
This was a prospective cohort study of low‐risk singleton pregnancies undergoing ultrasound assessment at 37 weeks. At study inclusion, biometry for estimated fetal weight (EFW), and fetoplacental Doppler variables (uterine artery pulsatility index (UtA‐PI), cerebroplacental ratio (CPR) and umbilical vein blood flow (UVBF) normalized by EFW) were measured. SGA was defined as a customized birth weight between the 3rd and 10th centiles, and FGR was defined as a birth weight < 3rd centile, according to local standards. Adverse perinatal outcomes included emergency Cesarean section for non‐reassuring fetal status, 5‐min Apgar score < 7 and neonatal acidosis at birth.
Results
A total of 946 pregnancies were included in the study. Of these, 89 (9.4%) were classified as SGA and 40 (4.2%) as FGR, with an overall rate of adverse perinatal outcome of 4.9%. At a fixed 10% false‐positive rate (FPR), the detection rate of SGA by EFW, UtA‐PI, CPR, UVBF and by a combination of Doppler variables (UtA‐PI and CPR) and EFW was 59.2%, 10.5%, 13.7%, 3.2% and 61.0%, respectively. At a fixed 10% FPR, the detection rate of FGR by EFW, UtA‐PI, CPR, UVBF and a combination of CPR and EFW centile was 83.3%, 13.9%, 27.8%, 13.9% and 88.6%, respectively. At a fixed 10% FPR, the detection rate of adverse perinatal outcome by EFW, UtA‐PI, CPR and UVBF was 19.2%, 9.2%, 23.1% and 16.9%, respectively, while combining EFW with Doppler variables (including CPR and UVBF normalized by EFW) improved the detection rate to nearly 30%.
Conclusion
In low‐risk pregnancies, Doppler evaluation at 37 weeks' gestation did not improve the prediction of SGA and FGR compared with that given by EFW alone, however, combining Doppler variables with EFW improved the prediction of adverse perinatal outcomes given by these parameters alone, although not markedly. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.