Grapes According to Only My Health.com, "Medical professionals encourage pregnant women to avoid grapes during pregnancy, especially in the last trimester, because of their heat content. The heat content in the stomach is said to lead to loose motions and diarrhea. Raisins, which are dried grapes, have also been encouraged to be avoided during pregnancy as well. The reason is because grapes have high amounts of resveratrol - a chemical that can cause toxicity in the expecting mother. For this condition to occur, you have to consume alot of grapes. Sour grapes are acidic and can lead to heartburn in pregnant women who are more prone to it. They do note that eating grapes during pregnancy can also give nutrients like vitamin A and C" (Khaliq). According to Bold Sky, "There is controversy over eating grapes during pregnancy. Black grapes are said to be problematic for pregnant women, because the skin is said to become non-digestable by the weaken digestive syst...