Are melanocytic nevi influenced by pregnancy? A dermoscopic evaluation.

BACKGROUND Dermoscopic data of melanocytic nevi (MN) in pregnancy are very limited and related to small groups of women. OBJECTIVE This study systematically analyzes dermoscopic parameters in a wide series of MN during and after pregnancy. METHODS Eighty-six MN on the back of 47 women were studied. Dermoscopic parameters, total dermoscopic score (TDS) according to Stolz's ABCD rule, and the sizes of the nevi were evaluated over time. RESULTS Progressive lightening of the nevi resulted at the end of pregnancy (p<.05) and after delivery (p<.001). Pigment network showed a progressive reduction in prominence and thickness (end of pregnancy, p<.05; after delivery, p<.01). At the end of pregnancy, vessels increased (p<.05) and a higher TDS was observed, with a significant reduction in both after delivery (vessels, p<.05; TDS, p<.01). Area changes were not statistically significant. CONCLUSIONS At the end of pregnancy, both vascular structures and TDS increased. These modifications were transient as the nevi recovered their prior appearance after delivery. The results indicate that an intrinsic influence of pregnancy may induce structural modifications without influencing the size of the nevi. Behavioral factors during the observational period, like a reduced exposure to sunlight reported by most of the women, may have influenced other characteristics, like global pigmentation and pigment network.