The first part is nipple and areola. During pregnancy, nipples and areola will definitely turn black and breasts will become bigger. This is because there is more estrogen in the body than before pregnancy, and the breast is slowly storing milk, which is convenient for children to drink breast milk after birth.
The second part is that the neck will turn black. This truth is the same as the above. Estrogen will not only be deposited on nipples and areola, but also on the neck. But seeing these phenomena, many little girls who love beauty may feel very sad or want to use makeup to cover it up, and even think that they have not done a good job in sun protection. In fact, these are all normal and will recover after you give birth to a baby.
Then there is the armpit, and the inside of the leg and abdomen tend to turn black. To sum up, these parts turn black because the amount of estrogen during pregnancy has doubled before pregnancy, so these places are prone to melanin precipitation. When a girl who is a first-time mother sees these phenomena, don't panic. These are normal phenomena, indicating that the baby is growing up in your stomach.