Precautions in Early Pregnancy The first trimester is a critical period of the entire pregnancy, and mothers need to pay special attention to their health. Here are the things you need to pay attention to during early pregnancy: First, pregnant women need to quit smoking, drinking, and other harmful substances. Smoking, drinking, and exposure to harmful substances can affect fetal development and may cause miscarriage and malformations. Secondly, pregnant women need to exercise moderately. Exercise can enhance the physical fitness and immunity of pregnant women and contribute to the healthy development of the fetus. However, pregnant women need to avoid strenuous exercise and prolonged standing or sitting. Also, pregnant women need to avoid tension and stress. Tension and stress can affect a pregnant woman’s body and mind