Fetal growth restriction (FGR) and respiratory morbidity in a very preterm birth cohort.

Abstract

Background: Approximately 5-10% of infants delivered at term gestation have FGR, though, prevalence in preterm cohorts is not known. Preterm FGR infants may be at risk of greater morbidity. The objectives were to ascertain the prevalence of FGR amongst premature infants and to ascertain respiratory morbidity. Method(s): The institution database was accessed for all preterm infants between 24-31+6 weeks GA admitted to the NICU during the period 2014-2016 from data annually submitted to ANZNN. FGR was assigned postnatally as birthweight <10th centile for GA. FGR infants were compared with an equal number of consecutively born GA and gender matched AGA infants. Result(s): During the period, 973 infants between 24-32 weeks GA were admitted to the NICU. Of these, 206 (27%) were FGR. Between 28-32 weeks GA, approximately 1/3rd were FGR. GA and birthweight of the FGR and AGA cohorts were (30.2 +/- 0.2vs30.1 +/- 0.2 weeks, p = 0.8 & 1132 +/- 43vs1499 +/- 54 g, p < 0.0001). While administration of antenatal steroids, surfactant, mechanical ventilation, sepsis & PDA were comparable, the respiratory outcomes were significantly worse in the FGR cohort. This included duration of respiratory support (days), home oxygen n (%) and CLD ([37 +/- 10 vs. 23 +/- 5 days, p = 0.016], [24 (11.6%) vs. 8 (3.8%), p = 0.005] & [53 (25.7%) vs. 28 (13.6%), p = 0.002]), respectively. Conclusion(s): This data supports the 'fetal programming' hypothesis, whereby exposure to utero-placental insufficiency can result in alterations predisposing to chronic respiratory disease. As greater respiratory morbidity occurred while postnatal variables were comparable, management of FGR cohorts needs to be individualized.