They’re many things pregnant women should not do. Citrus food, fried and fatty foods tend to bring on heartburn because they take longer to digest. Avoid tobacco, its extremely harmful to your unborn baby and to yourself. Caffeine stimulates the heart and brain, and is an addictive substance with drug-like qualities. Pregnant women should avoid stripping paint, because if the house was built before 1978, there is a good chance some of the layers contain lead. Stress can cause constipation, back pain, insomnia, and even lead to pre-term birth or low birth weight.