Maternal Restriction of Polyphenols and Fetal Ductal Dynamics in Normal Pregnancy: An Open Clinical Trial

BACKGROUND: We have recently demonstrated reversal of fetal ductal constriction after dietary maternal restriction of polyphenol-rich foods (PRF), due to its inhibitory action on prostaglandin synthesis. OBJECTIVE: To test the hyphotesis that normal third trimester fetuses also improve ductus arteriosus dynamics after maternal restriction of polyphenols. METHODS: Open clinical trial with 46 fetuses with gestational age (GA) ≥ 28 weeks submitted to 2 Doppler echocardiographic studies with an interval of at least 2 weeks, being the examiners blinded to maternal dietary habits. A validated food frequency questionnaire was applied and a diet based on polyphenol-poor foods (<30mg/100mg) was recommended. A control group of 26 third trimester fetuses was submitted to the same protocol. Statistics used t test for independent samples. RESULTS: Mean GA was 33±2 weeks. Mean daily maternal estimated polyphenol intake (DMPI) was 1277mg, decreasing to 126mg after dietary orientation (p=0.0001). Significant decreases in systolic (SDV) and diastolic (DDV) ductal velocities, and RV/LV diameters ratio, as well as increase in ductal PI were observed [DSV=1.2±0.4m/s (0.7-1.6) to 0.9±0.3m/s (0.6-1.3) (p=0.018); DDV=0.21±0.09m/s (0.15-0.32) to 0.18±0.06m/s (0.11-0.25) (p=0.016); RV/LV ratio =1.3±0.2 (0.9-1.4) to 1.1±0.2 (0.8-1.3) (p=0.004); ductal PI=2.2±0.03 (2.0-2.7) to 2.4±0.4(2.2-2.9) (p=0.04)]. In the control group, with GA of 32±4 weeks, there were no significant differences in DMPI, mean SDV, DDV, PI and RV/LV ratio. CONCLUSION: The oriented restriction of third trimester maternal ingestion of polyphenol-rich foods for a period of 2 weeks or more improve fetal ductus arteriosus flow dynamics and right ventricular dimensions.