Greetings! The pigmentation that commonly occurs on the face after pregnancy is known as melasma. This occurs due to the hormonal changes in the body during pregnancy. Hydroquinone based creams are useful in treating this pigmentation. However, the most important step in managing this is Sunprotection. Protection from sunrays (especially 10am to 4pm) with a good medicated sunscreen of atleast spf30 is necessary. Routine sunscreens may not give adequate protection. Kindly consult a dermatologist for a detailed treatment regimen.