Pregnancy can trigger melasma due to the hormonal changes that occur in the body during pregnancy. Specifically, the increase in estrogen and progesterone levels can stimulate the production of melanin, the pigment that gives color to the skin. This can result in the development of dark patches on the face, particularly on the cheeks, forehead, nose, and upper lip.
Pregnancy-related melasma is sometimes referred to as "chloasma" or the "mask of pregnancy." It is more common in women who have a family history of the condition or who have previously experienced melasma. The condition typically develops during the second or third trimester of pregnancy and can persist after delivery.
To prevent pregnancy-related melasma, it is important to protect the skin from the sun by wearing protective clothing, such as hats and long sleeves, and using sunscreen with a high SPF. If melasma develops during pregnancy, it may improve after delivery, but it can also persist and may require treatment to improve its appearance. However, it's important to consult with a dermatologist before using any skincare products or undergoing any treatments during pregnancy.