Cardiovascular Hemodynamic Changes After Antenatal Corticosteroids in Growth Restricted and Appropriate for Gestational Age Fetuses.

PURPOSE:  To investigate hemodynamic effects after antenatal corticosteroids (ACS) administration in appropriate for gestational age (AGA) and early growth restricted (GR) fetuses by measurement of Doppler cardiovascular function parameters.

MATERIALS AND METHODS:  Prospective cohort study. AGA and GR singleton pregnancies receiving ACS for fetal lung maturation between 24 + 0 - 33 + 6 weeks were enrolled. Feto-placental vascular hemodynamics were studied by: umbilical artery (UA) pulsatility index (PI), middle cerebral artery (MCA) PI, renal artery (RenA) PI. Cardiac function was evaluated by ductus venosus (DV) PI and by echocardiographic parameters: E to A wave ratios (E/A) and mitral and tricuspid annular plane systolic excursion (MAPSE and TAPSE) for diastolic function, left and right myocardial performance index (MPI) for overall (diastolic and systolic) function. A single operator performed all the measurements at 3 different time points (E): E0 before or within 4 hours of ACS administration (baseline examination), E1 24 - 48 hours after the first dose and E2 7 days after the second dose of ACS. The values were expressed as z-scores. Pairwise comparisons with paired t-test were performed to compare measurements before and after exposure to ACS.

RESULTS:  25 AGA and 20 GR fetuses (mean gestational age: 31 + 1 and 30 + 6, respectively) were included in the analysis. In the AGA group ACS administration was associated with a significant reduction in UA PI. In the GR fetuses ACS temporarily (E0-E1) restored UA-end diastolic flow (EDF) in 6 of 9 fetuses with A/R-EDF ("Return of EDF phenomenon") and produced a significant increase (worsening) in right MPI (both in E1-E2 and in E0-E2).

CONCLUSION:  ACS administration is associated with UA vasodilation in both AGA and GR fetuses and with an increase in right MPI in the latter group. This suggests a worsening in cardiac function in GR fetuses.