Chloasma is a required hypermelanosis of sun-exposed areas occurred during pregnancy and it can affect 50-70% of pregnant women. It presents as symmetric hyperpigmented macules, which can confluent or punctuate. The most common locations are the cheeks, the upper lip, the chin and the forehead.

How does chloasma occur?

What causes chloasma? With chloasma, the pigment-producing cells of the skin (i.e., melanocytes) become overactive and produce too much melanin, which leads to hyperpigmentation. While the exact cause of chloasma is often unclear, there seem to be several contributing factors associated with its onset.

How early in pregnancy does melasma start?

Melasma may start at any point in your pregnancy, though it most commonly begins in the second or third trimester. Again, there are a variety of factors at play when it comes to darkening pigment. Your skin color and type may make this condition more or less noticeable.