Dreams are normal physiological phenomena. Some dreams can cause frightening and extremely disturbing feelings, such as being chased, falling from a height, getting lost and making a fool of oneself in public, also called nightmares. Nightmares are frequent in normal people, as well as in pregnant women, and there is no such thing as a sign. Dreams are a combination of various pieces of information stored in the body and brain during sleep to produce a mood, is the release of the real emotions in the brain, pregnant women have nightmares for the following main reasons: 1, pregnancy factors: after pregnancy, the body progesterone levels rise, resulting in pregnant women are more sensitive than before, prone to mood swings, and even minor stimuli during the day can cause abnormal excitement in the cerebral cortex at night 2, physiological factors: after pregnancy fetal growth pregnant women gradually urinary frequency, malnutrition, calcium deficiency and other symptoms, resulting in physical discomfort, seriously affect the night sleep; 3, psychological factors: psychological pressure roughly mental tension, such as fear of fetal sex, fetal health and the birth process, resulting in internal fear, too much thinking, “day thinking, night dreaming “The situation. In summary, nightmares are mostly due to psychological and physiological factors, pregnant women have nightmares and no specific signs, but long-term nightmares lead to poor rest will directly affect the growth of the fetus, to be corrected in a timely manner.