7 months pregnant can not sleep at night due to environmental factors, physiological factors, emotional and psychological factors and so on. 1. Environmental factors: most pregnant women in their seventh month of pregnancy are more sensitive to changes in the surrounding environment. If the environment around the pregnant woman is too noisy at night, it is easy to affect the pregnant woman’s sleep, resulting in sleepless nights. 2. Physiological factors: pregnant women 7 months pregnant uterus increased significantly, the body of relaxin and other increases, resulting in pregnant women prone to back discomfort, poor sleep quality. When a pregnant woman is lying on her back in late pregnancy, the enlarged uterus compresses the inferior vena cava, producing symptoms such as chest tightness and affecting sleep. Low calcium in pregnant women is also prone to cause muscle spasms, affecting sleep. 3. Emotional and psychological factors: pregnant women due to changes in hormone levels, prone to mood swings, mental stress, prone to insomnia, and even depression and other symptoms, resulting in sleepless nights. Insomnia in 7 months of pregnancy should be timely consultation, under the guidance of the doctor to identify the causes and give appropriate treatment.