Maternal leptin and body composition in the first trimester of pregnancy

Background. Leptin is produced mainly by adipocytes. Levels are increased in women with obesity and during pregnancy. Increased levels are also associated with pregnancy complications such as, pre-eclampsia and gestational diabetes mellitus. Objective. We studied what component of body composition correlated best with maternal leptin in the first trimester of pregnancy and, whether maternal leptin correlated better with visceral fat rather than fat distributed elsewhere. Subjects and methods. Women were recruited in the first trimester. Maternal adiposity was measured using body mass index and advanced bioelectrical impedance analysis. Maternal leptin was measured using an enzyme-linked immunosorbent assay technique. Results. Of the 100 subjects studied, the mean leptin concentration was 37.7 ng/ml (range: 2.1-132.8). Leptin levels did not correlate with gestational age in the first trimester, maternal age, parity or birth weight. Serum leptin correlated positively with maternal weight and body mass index, and with the different parameters of body composition. On multiple regression analysis, serum leptin correlated with visceral fat but not fat distributed elsewhere. Conclusions. Visceral fat is the main determinant of circulating maternal leptin in the first trimester of pregnancy. This raises the possibility that maternal leptin in early pregnancy may be a marker for the development of metabolic syndrome, including diabetes mellitus.