Exposure to UV rays (natural or artificial) not only increases the risk of skin cancer and premature wrinkles and age spots, it can also exacerbate a common pregnancy skin condition called melasma, or the "mask of pregnancy."

Melasma, also known as chloasma, appears as dark spots on the face - especially the cheeks, forehead, upper lip, and nose. It may show up without any sun exposure, but sunlight can make the spots darken and spread. In general, brunettes are more prone to developing melasma than blondes, as are women taking oral contraceptives and those who are pregnant.

Using sunblock every day may protect against melasma; however, the best way to prevent it is to keep your skin out of the sun completely. When outdoors, wear a wide-brimmed hat or stay in the shade. Although most melasma fades after delivery, some spots may never return to their pre-pregnancy appearance.

Other parts of your body are less susceptible to changes in pigment during pregnancy, but tanning is still just as unhealthy during pregnancy as it is any other time. In addition, the safety of self-tanning lotions is still unclear, and many experts recommend against using them during pregnancy.