Maternal restriction of polyphenols and fetal ductal dynamics in normal pregnancy: an open clinical trial.

backgroundWe 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.

objectiveTo test the hyphotesis that normal third trimester fetuses also improve ductus arteriosus dynamics after maternal restriction of polyphenols.

methodsOpen 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 (<30 mg/100 mg) was recommended. A control group of 26 third trimester fetuses was submitted to the same protocol. Statistics used t test for independent samples.

resultsMean GA was 33 ± 2 weeks. Mean daily maternal estimated polyphenol intake (DMPI) was 1277 mg, decreasing to 126 mg 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 ± 0.4 m/s (0.7-1.6) to 0.9 ± 0.3 m/s (0.6-1.3) (p = 0.018); DDV = 0.21 ± 0.09 m/s (0.15-0.32) to 0.18 ± 0.06 m/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.

conclusionThe 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.