Prediction of Neonatal Outcome by Umbilical Artery Velocimetry in Intrauterine Growth Restriction: A Study in Western Nepal

Abstract

The introduction of Doppler velocimetry to obstetrics offered a noninvasive and safe imaging modality of indirectly assessing the fetal and uteroplacental circulation. Obstetric Doppler ultrasound plays an important role in detecting Intra Uterine Growth Restriction (IUGR). The early diagnosis of IUGR with the help of abnormal flow patterns in umbilical, uterine and middle cerebral arteries using Doppler ultrasound may help in reducing perinatal and neonatal mortality and morbidity as well as reducing perinatal complications. This provides for timely interventions to prevent progression from IUGR to Intrauterine death (IUD).The study was carried out in 140 patients in Manipal Teaching Hospital, Pokhara for a period of twenty months from October 2013 to June 2015. All the cases presented to Radiology department for obstetric Doppler with clinical suspicion of IUGR were taken up for the study and obstetric doppler of umbilical artery was performed. Seventy two out of 140 (51.50%) had abnormal umbilical artery Doppler velocimetry. Fifty seven out of these 72 subjects (positive predictive value – 79.2%) with abnormal umbilical artery Doppler were later born with small for gestational age (SGA). The S/D ratio of umbilical artery of 3 or greater was considered abnormal in predicting IUGR and it showed sensitivity, specificity, positive predictive value, and negative predictive value of 76%, 76.9%, 79.2% and 73.5% respectively. Admission to the Neonatal Intensive Care Unit (NICU) and incidence of perinatal and neonatal mortality increased with the worsening of Doppler velocimetry. Twenty seven out of one hundred and forty neonates developed perinatal asphyxia, out of which 26 (96.3%) had abnormal umbilical artery velocimetry. NICU admissions comprised of a total of 30 neonates, out of which 27(90%) had abnormal umbilical artery Doppler velocimetry prenatally. Fifteen out of thirty didn’t survive, all of whom had abnormal umbilical artery Doppler velocimetry prenatally. There were 3 still born and all of them had abnormal umbilical artery velocimetry prenatally. The study could underline that abnormal Doppler velocimetry has a fairly good sensitivity and specificity for predicting IUGR and it is related with poor neonatal outcomes.