During pregnancy, various physiological functions may change accordingly, insomnia is a common clinical symptom during pregnancy, and the causes of insomnia in mid-pregnancy mainly include: 1. 2, after pregnancy, due to changes in the endocrine function of the body, the corresponding changes in the function of the plant nerves, increased sensitivity to various stimuli, if the rest environment temperature is not suitable, too much noise, will also affect the quality of sleep of pregnant women. 3, some pregnant women in mid-pregnancy insomnia symptoms related to organic diseases, such as iron deficiency anemia, hyper- or hypothyroidism. The reason for insomnia in the middle of pregnancy is related to organic diseases, such as iron deficiency anemia, hyper- or hypothyroidism, etc.