Increased pigmentation of the labia minora, the nipples and the linea alba on the abdomen is a normal process during pregnancy and is due to increased oestrogen and progesterone.
In turn, the increased circulation of hormones leads to hyperplasia of melanocytes, the cells responsible for producing melanin, the pigment of our skin. Hyperpigmentation of the skin may also appear on the face, the well-known chloasma of pregnancy. For these reasons, avoiding sun exposure and using creams with a high sun protection factor are recommended.