Patches of skin could darken during pregnancy, due to hypersensitve skin pigmentation. Your skin is extra sensitive during pregnancy and you could experience higher levels of melasma. Melasma is when the pigmentation of your skin darkens in patches, especially on the face and arms. This darkening of the skin is called the “pregnancy mask” because it most often affects the face. It happened to a friend of mine and really did look like she was wearing a mask because it covered her face but leaving spaces around the edges. If I hadn’t have seen the effects on my friend, I probably would not have known about changes to skin pigmentation during pregnancy. As someone with very sensitive skin, I made sure to cover myself up well and protect myself from the sun.
In the case of my friend, the changes were permanent.