Ghrelin levels in cord blood from concordant and discordant twin pairs: association with birth weight and postnatal catch-up growth.

OBJECTIVE: To determine whether cord blood ghrelin levels in discordant and concordant twins predict postnatal catch-up growth. METHODS: After obtaining parental consent, cord blood samples were collected at delivery for total ghrelin analysis. Infant weight, length and head circumference were obtained at birth, 2, 4, and 6 months of age. Data points post-discharge were obtained from the pediatrician's office or via parent contact. Pearson correlation evaluated the relationship between cord blood ghrelin levels and postnatal catch-up growth. RESULTS: There was a statistically significant correlation between cord blood ghrelin levels and birth weight among concordant twins, but not among the discordant twins. Cord blood ghrelin levels did not predict postnatal growth at 6 months of age overall, but did so in the subset of monochorionic, discordant pairs. CONCLUSION: Cord blood ghrelin levels did not correlate overall with birth size or postnatal catch-up growth in concordant and discordant twin pairs, but did so in selected subsets. Further studies are needed.