Effect of coffee intake on blood flow and maternal stress during the third trimester of pregnancy

Objective: To investigate the effects of maternal ingestion of an ordinary dose of coffee on maternal stress and placental and fetal blood circulation during the third trimester of pregnancy. Methods: We performed a Doppler blood flow analysis for 10 women in the third trimester of pregnancy before and after they drank a cup of coffee. Salivary samples were collected from the 10 pregnant women and 14 nonpregnant controls just before coffee intake and 30 min later. Salivary cortisol levels and chromogranin A titers were determined. Results: Coffee intake had no effect on maternal or fetal blood flow. Among the pregnant women, Salivary cortisol levels were significantly reduced after coffee intake but salivary chromogranin A concentration was not significantly different before and after coffee intake. Conclusion: The reduced salivary cortisol levels suggest that coffee intake decreases maternal stress during pregnancy.