Darkening of the armpits of pregnant women can be caused by changes in hormone levels in the body, among other things. But very few pregnant women may also have some relationship with genetic factors. The darkening of the armpits of pregnant women is a normal manifestation of pregnancy. After pregnancy, the level of estrogen in the pregnant woman’s body will change, and there will be an increase in the secretion of estrogen. This leads to a rapid increase in human chorionic gonadotropin, causing melanin deposition. Resulting in the darkening of the armpits, areolas, labia majora, labia minora and so on. In addition, the darkening of the armpits of pregnant women may also be related to genetic factors and individual physique. Therefore, when a pregnant woman finds that her armpits are darkened, she should not worry too much, keep her armpits clean and hygienic, and avoid excessive humidity. It is recommended that pregnant women have regular obstetric examinations, which will not adversely affect the development of the pregnant woman herself and the fetus. During pregnancy, pay attention to more rest, at the same time should relax, avoid tension, anxiety, any discomfort should be timely to the hospital, by the doctor to clarify the diagnosis, and cooperate with the doctor to deal with the symptoms.