Impairment of fetal growth potential and neonatal encephalopathy

Objective: This study was undertaken to determine the frequency of growth impairment in neonates with encephalopathy. Study Design: In a case-control design, neonates with neonatal encephalopathy (NE) meeting criteria for an acute intrapartum hypoxic event (IHE, N = 21) and those who did not meet these criteria (n = 20) were compared with controls. The controls were 42 neonates without complications matched 2:1 for gestational age with IHE cases. The percentile of growth potential, a measure of the weight expected in the absence of pathological conditions, was calculated for each fetus. Results: More neonates with NE with and without IHE were below the 10th percentile of growth potential compared with controls (7/21 [33%] and 6/20 [30%] vs 1/42 [2.4%], odds ratio [95% CI] = 20.5 [2.2-114.0] and 17.6 [1.8-102.5], respectively). These associations remained significant after controlling for gestational age and birth weight. Conclusion: A large proportion of neonates with NE demonstrate signs of antepartum injury reflected in the impairment of their growth. This association was similar in the presence or absence of IHE, indicating that antepartum injury has a causative rather than predisposing character in many cases of IHE.