Plusieurs essais cliniques randomisés (ECR) suggèrent un effet bénéfique des flavanols du chocolat sur la tension artérielle (TA) et la fonction endothéliale (FE). Aucun ECR n’a évalué ces effets chez les femmes enceintes. L’objectif de cet ECR pilote est de vérifier la faisabilité d’un ECR de grande envergure évaluant les effets du chocolat sur la FE et la TA de femmes enceintes. Quarante quatre femmes enceintes ont été randomisées au groupe chocolat riche en flavanols (n=23) ou à teneur faible en flavanols (n=21). À la randomisation, 60, 120 et 180 minutes après la prise unique de chocolat (40 g) et 6 et 12 semaines après une prise quotidienne de chocolat (20 g), la FE, la TA, les concentrations sériques de flavanols et de théobromine (CFT) ont été évaluées. Après 180 minutes, la consommation de chocolat riche en flavanols s’est accompagnée d’une augmentation significative de flavanols et de théobromine. Aucun changement significatif sur la FE et la TA n’a été observé. / Background: Several randomized clinical trials (RCTs) indicate that flavanol-rich chocolate has beneficial effects on flow-mediated dilation (FMD) and blood pressure (BP). However, no RCTs have evaluated these outcomes in pregnant women. Aims: The objective of this 2-group, parallel, double-blind RCT was to examine the effects of flavanol-rich chocolate on FMD and BP in pregnant women with normal BP. Methods: Forty-four healthy, pregnant women were randomized to the high-flavanol (n = 23) or low-flavanol (n = 21) chocolate consumption for 12 weeks. At randomization (0, 60, 120 and 180 min after a single 40-g dose of chocolate), 6 and 12 weeks after daily 20-g chocolate intake, we evaluated plasma concentrations of flavanols and theobromine, as well as the FMD and BP. Results: Plasma epicatechin was significantly increased (p< 0.001) 180 min after the consumption of 40-g high-flavanol chocolate compared to low-flavanol chocolate. Theobromine concentrations were significantly higher 180 min and 12 weeks after the intake of experimental chocolate or low-flavanol chocolate (p< 0.001). FMD and blood pressure were not different between the 2 groups at all pre-defined time periods. No other significant within-group or between-group changes were observed. Conclusion: These results confirm the feasibility of a large-scale RCT comparing daily consumption of flavanol-rich chocolate to an equivalent placebo during pregnancy and demonstrate higher plasma concentration of epicatechin in the intervention group.