“Melasma is a very common condition in pregnancy and is due to hyperpigmentation related to normal hormonal changes that accompany pregnancy. It can also be caused by oral contraceptives and is more common in dark-skinned persons.
High-potency broad-spectrum sunscreens may help prevent melasma, or at least prevent worsening of the condition (SOR C). Topical retinoids, hydroquinone, and corticosteroids can also be helpful, but are usually reserved for postpartum use and require months of treatment. Other treatments include azelaic acid, chemical peels, kojic acid, cryosurgery, and laser treatment (SOR B). Melasma usually improves spontaneously after delivery, but it may be prolonged or worsened by oral contraceptive use. It does not increase the risk of developing skin malignancies.
Ref: Tunzi M, Gray G: Common skin conditions during pregnancy. Am Fam Physician 2007;75(2):211-218. 2) Habif TP:Clinical Dermatology: A Color Guide to Diagnosis and Therapy, ed 5. Mosby Elsevier, 2010, pp 772-774.” ABFM