Nevi and melanoma in pregnancy.

The influence of pregnancy on melanocytic nevi and malignant melanoma (MM) continues to be a controversial issue. Over the past 50 years, case reports and uncontrolled studies have suggested that nevi are more likely to become malignant during pregnancy, and MM diagnosed during pregnancy has a poor prognosis. Clinical and laboratory observations suggested that pregnancy-associated hormones may influence nevi and MM. Recent clinical and laboratory evidence suggests, however, that pregnancy does not influence the prognosis of MM, nor does it seem to cause significant changes in nevi. A clear link between hormones and MM has not been established. An analysis of this evidence is presented along with practical recommendations for the patient.