Pregnancy Serum DLK1 Concentrations Are Associated With Indices of Insulin Resistance and Secretion.

CONTEXT: Delta like noncanonical notch ligand 1 (DLK1) is a paternally expressed imprinted gene that encodes an epidermal growth factor repeat-containing transmembrane protein. A bioactive, truncated DLK1 protein is present in the circulation and has roles in development and metabolism. OBJECTIVE: We sought to investigate links between maternal pregnancy circulating DLK1 concentrations and: (1) maternal and fetal DLK1 genotypes, (2) maternal insulin resistance and secretion, and (3) offspring size at birth. PATIENTS, DESIGN, AND SETTING: We measured third-trimester maternal serum DLK1 concentrations and examined their associations with parentally transmitted fetal and maternal DLK1 genotypes, indices of maternal insulin resistance and secretion derived from 75-g oral glucose tolerance tests performed around week 28 of pregnancy, and offspring size at birth in 613 pregnancies from the Cambridge Baby Growth Study. RESULTS: Maternal DLK1 concentrations were associated with the paternally transmitted fetal DLK1 rs12147008 allele (P†=†7.8†×â€