1. What is backache in early pregnancy? Backache in early pregnancy refers to the symptoms of waist discomfort experienced by pregnant women in the early stages of pregnancy. This symptom usually appears in the first or second month of pregnancy and will gradually reduce or disappear as the fetus develops and grows. 2. Why does backache occur in early pregnancy? 1. Hormonal changes: In the early stages of pregnancy, hormonal levels in the body undergo great changes. These changes may lead to muscle relaxation and joint loosening, thereby causing waist discomfort. 2. Increase: As the fetus grows and grows, it will put pressure on the surrounding tissues and nerves, causing backache.