Brief Report - Abnormal Doppler Flow Velocimetry in the Growth Restricted Foetus as a Predictor for Necrotising Enterocolitis

Background: Obstetric decision- making for the growth restricted foetus has to take into consideration the benefits and risks of waiting for pulmonary maturity and continued exposure to hostile intra-uterine environment. Necrotising Enterocolitis (NEC) results from continued exposure to hostile environment and is an important cause of poor neonatal outcome. Aims: To evaluate the predictive value of abnormal Doppler flow velocimetry of the foetal umbilical artery for NEC and neonatal mortality. Settings and Design: A retrospective study carried out at a tertiary care centre for obstetric and neonatal care. Materials and Method: Seventy-seven neonates with birth weight less than 2000 gm, born over a period of 18 months were studied. These pregnancies were identified as having growth abnormalities of the foetus. Besides other tests of foetal well-being, they were also subjected to Doppler flow velocimetry of the foeto-placental vasculature. Obstetric outcome was evaluated with reference to period of gestation and route of delivery. The neonatal outcome was reviewed with reference to birth weight, Apgar scores and evidence of NEC. Statistical Analysis used: Chi square test. Results: In the group of patients with Absent or Reverse End Diastolic Frequencies (A/R EDF) in the umbilical arteries, positive predictive value for NEC was 52.6%, (RR 30.2; OR 264). The mortality from NEC was 50%. When umbilical artery velocimetry did not show A/REDF, there were no cases of NEC or mortality. Abnormal umbilical or uterine artery flow increased the rate of caesarean section to 62.5% as compared to 17.6% in cases where umbilical artery flow was normal. Conclusion: In antenatally identified pregnancies at risk for foetal growth restriction, abnormal Doppler velocimetry in the form of A/REDF in the umbilical arteries is a useful guide to predict NEC and mortality in the early neonatal period. (J Postgrad Med 2002;48:182-185)

Keywords
Doppler flow velocimetry, Umbilical flow velocimetry, Necrotising Enterocolitis, Growth restriction, Term pregnancy