Impact of Maternal Corticosteroids on Foetal and Uteroplacental Blood Flow Dynamics in Preterm Pregnancies with Growth Restricted Foetus: A Prospective Observational Study

Introduction: Foetal Growth Restriction (FGR) is a critical condition where a foetus fails to achieve its genetically determined growth potential for gestational age. Studies using doppler ultrasonography have shown beneficial modifications in blood flow indices following corticosteroid administration, though there are some concerns regarding potential adverse effects. Aim: To evaluate the effects of maternal corticosteroids on foetal and uteroplacental blood flow dynamics in preterm pregnancies complicated by FGR. Materials and Methods: A prospective observational hospitalbased study was conducted at a Tertiary Care Centre in Puducherry, India over a period of 18 months from October 2022 to March 2024, involving pregnant women between 28 to 36 weeks of gestation diagnosed with FGR with normal doppler as per delphi consensus criteria. A total of 84 patients were enrolled in the study. Pretreatment doppler indices were recorded for Umbilical Artery (UA), Middle Cerebral Artery (MCA), and maternal Uterine Artery (UtA) at ‘0’ hour and 24-48 and 72- 96 hours following corticosteroid administration, and neonatal outcome in terms of Appearance, Pulse, Grimace, Activity, and Respiration (APGAR) score and Neonatal Intensive Care Unit (NICU) admission were observed. Statistical analysis was done to determine the significance of the observations. Results: Maternal corticosteroid administration significantly increased the UA Pulsatality Index (PI) at 24-48 hours (mean difference=0.107, p<0.0001) with return towards baseline at 72- 96 hours (mean difference=0.020, p=0.722). MCA PI showed significant reductions at 24-48 hours (mean difference = -0.139, p<0.0001) and 72-96 hours (mean difference = -0.181, p<0.0001) compared to baseline. The UtA PI remained stable throughout the observation period. 51% neonates had APGAR score <7 at five minutes and needed NICU admission. Conclusion: Maternal corticosteroids appear to positively influence foetal and uteroplacental blood flow in pregnancies affected by FGR. These findings may have clinical implications, enhancing strategies for the management of preterm FGR and improving outcomes for affected neonates.