Plus, you're also at increased risk for melasma, often called the "mask of pregnancy," a discoloration of the skin that leads to brown patches on the face. Increased estrogen levels combined with sun exposure can raise the activity of pigment-producing cells, explains Sarah Myers, MD, an associate professor of dermatology at the Duke University Medical Center, in Durham, North Carolina. Wearing sunscreen -- one that blocks both UVA and UVB rays and has an SPF of 30 or higher -- and a hat can help prevent melasma. Reapply sunscreen every two hours, more often if you're sweating or swimming.
For many women, melasma fades naturally after they give birth. But if it does not, a dermatologist can prescribe a bleaching cream. "A lot of these creams contain ingredients that are harmful to a developing baby during pregnancy and breastfeeding, so you'll need to wait until you're done to use them," says Diane Berson, MD, an assistant professor of dermatology at the Weill Medical College of Cornell University, in New York City. "For darker patches, a light chemical peel or a laser treatment may help."