Despite the potential benefits of a diet rich in polyphenols, a high consumption of these substances in the third trimester of pregnancy may reduce plasma levels of PGE2 and result in DA constriction,so that a restriction in their ingestion during this period is already recommended.This functional problem has high prevalence and may result in severe fetal and neonatal complications. These considerations raised the hypothesis that reversal of fetal ductal constriction after maternal restriction of polyphenol-rich foods is accompanied by increased in prostaglandin E2 levels. Demonstration of this effect would represent an advancement in knowledge and might result in changes in dietary guidance during pregnancy and prevention of perinatal complications, with potential impact in terms of public health.