Associate Professor Monash University Melbourne, Victoria, Australia
Background: Intraventricular haemorrhage (IVH) is a common neuropathology in preterm infants. Fetal growth restriction (FGR), secondary to placental insufficiency, is also associated with preterm birth. Objective: Preclinical studies have shown FGR adversely affects the neurovasculature prompting us to ask whether FGR is over-represented in very preterm infants with IVH? Design/Methods: Data was obtained from the Australian and New Zealand Neonatal Network for all infants born < 32 weeks’ gestation (2014-2019 inclusive). IVH severity was classified according to the Papile IVH definition. FGR was defined according to the Delphi consensus as birth weight < 3rd percentile for gestation and sex, or birth weight < 10th percentile with abnormal antenatal uteroplacental Dopplers. Ordinal and binary regressions were performed. Odds ratio, confidence interval, and p-value ( < 0.05) were reported. Results: A total of 20,550 very preterm newborns (mean(SD) gestational age, 28.3(2.2) weeks, birth weight 1201.1(383.9) grams) were included. Overall incidence of IVH was ~20% and increased with decreasing gestation at birth (p= < 0.0001). The incidence of FGR was 6.2%. Contrary to our hypothesis, presence of FGR ( < 10th percentile+Dopplers) was significantly less in those with IVH compared to those without IVH (4.4% versus 6.7%, respectively, p=0.003). FGR also decreased the odds of developing severe IVH (p=0.001). Severe FGR ( < 3rd percentile) did not influence rates of IVH (1.9% with IVH, versus 2.1% without IVH, p=0.41).
Conclusion(s): FGR < 10th, but not < 3rd, percentile was associated with reduced rates and severity of IVH development. We are now using our preclinical studies to better understand why rates of IVH are lower in infants with FGR < 10th with placental insufficiency.
