Maternal Ramadan Fasting and Fetal Cardiac Function: Subclinical Hemodynamic Alterations Revealed by Doppler Evaluation

Backround and Objectives: To evaluate the impact of maternal Ramadan fasting on fetal cardiac function and hemodynamics using comprehensive Doppler echocardiography, emphasizing subclinical myocardial and circulatory adaptations. Materials and Methods: In this prospective study, 203 healthy singleton pregnancies between 24 and 32 weeks of gestation were examined—102 women who fasted for ≥ 10 days during Ramadan and 101 non-fasting controls. The study was prospectively registered with the National Clinical Trial (NCT06900257, registration date 23 March 2025). Doppler assessments included umbilical, middle cerebral, and ductus venosus pulsatility indices (PI), cerebroplacental ratio, and cardiac parameters: left and right myocardial performance indices (LV MPI, RV MPI), tricuspid and mitral annular plane systolic excursions (TAPSE, MAPSE), cardiothoracic ratio (CTR), and amniotic fluid index (AFI). Statistical analyses were performed using IBM SPSS v25.0 and Python 3.10, including correlation, regression, and ROC analysis. Results: Fasting pregnancies demonstrated significantly higher MCA PI (p < 0.001), LV MPI (p < 0.001), RV MPI (p = 0.041), and CTR (p < 0.001), and lower AFI (p < 0.001) than controls. Umbilical and ductus venosus PI, TAPSE, and MAPSE did not differ significantly. LV MPI correlated positively with CTR (r = 0.33) and inversely with AFI (r = − 0.42). Fasting independently predicted increased LV MPI and decreased AFI. ROC analysis showed limited predictive power of MPI for low AFI (AUC = 0.52). Conclusions: Maternal Ramadan fasting induces mild, reversible fetal cardiovascular adaptations—characterized by increased MPI and MCA PI and reduced AFI—without evidence of fetal distress. These findings emphasize fetal hemodynamic resilience but support individualized monitoring during fasting in pregnancy.