Plasma Kisspeptin Levels in Newborn Infants with Breast Enlargement.

OBJECTIVE: Kisspeptin levels have been reported in children with premature thelarche, precocious puberty and adolescent gynecomastia, but there are no reports on kisspeptin levels in the neonatal period. This study aimed to investigate plasma kisspeptin hormone levels in newborns with and without breast enlargement. METHODS: Plasma kisspeptin levels and other related biochemical variables were investigated in this prospective study conducted on 40 (20 girls and 20 boys) newborn infants with breast enlargement and on 40 healthy control infants (20 girls and 20 boys). Two-milliliter venous blood samples were taken in hemogram tubes with K2EDTA. Kisspeptin assays were performed using the enzyme-immunoassay method. RESULTS: Mean plasma kisspeptin levels were 0.6 ± 0.2 ng/mL in the study group and 0.5 ± 0.2 ng/mL in the control group. Plasma kisspeptin concentrations were significantly higher in the study group (p=0.039) and also showed a correlation with serum prolactin levels (p=0.006). Significant correlations were also determined between plasma kisspeptin and luteinizing hormone concentrations (p=0.05, r=0.312). CONCLUSION: The findings of this study suggest that plasma kisspeptin and serum prolactin levels may be involved in the physiopathology of breast enlargement in newborns.