The darkening of the armpits after pregnancy may be due to the excessive secretion of estrogen in the body after pregnancy, thus causing the skin in the folds to become darker and darker. Generally, no special treatment is needed. After the delivery of the baby, the black color of the area can be restored automatically or gradually diminished as the level of estrogen in the body decreases. If you are pregnant and your armpits have become black, from a cosmetic point of view, you can also use bleaching methods to deal with it, you can take local injections of hydrophobic needles, such as injections of hyaluronic acid can play a role in improving the black.