CHANGES OF MATERNAL SERUM LEPTIN LEVELS DURING PREGNANCY

Maternal leptin levels in serum and urine, their relations to maternal weight and body mass index, were examined in 9 healthy pregnant women from the 12th week of gestation until term. Serum leptin concentratio n was found to increase progressively during the first two trimesters followed by a slight decline thereafter. The peak value of 27.6 +/- 1 5.3 ng/ml (mean +/- SD) concentration was reached at the 28th week. Se rum leptin levels during the first two trimesters correlated significa ntly with maternal weight (p = 0.002) and body mass index (p = 0.002) but such a relationship was absent during the third trimester, Leptin could be detected only in about half of urine samples; its concentrati ons proved to be independent of serum values. No correlation was found between maternal serum leptin levels and the birth weight of neonates , Maternal leptin levels appear to refer to alterations in maternal fa t tissue mass that occur during pregnancy.