Clin Endocrinol (Oxf)

Objective Maternal blood leptin levels are positively associated with adiposity. Recent studies suggest that leptin is also abundantly produced by the placenta and may function as a regulator of fetal growth. Our goal was to examine mid-pregnancy levels of leptin in maternal blood in relation to birthweight for gestational age (BW/GA) and timing of delivery after accounting for maternal pre-pregnancy body mass index (prepreg-BMI) and pregnancy complications. Patients Data were from 1,304 sub-cohort mother/infant pairs who participated in the Pregnancy Outcomes and Community Health (POUCH) Study (1998–2004). Measurements Leptin levels, measured at 16–27 weeks’ gestation, were log-transformed. Geometric mean (GMean) leptin levels were estimated by weighted linear regression with gestational age at blood draw as a covariate. GMean was re-transformed to the original scale for reporting. Results Using the GMeans leptin in mothers of term appropriate-for-gestational age (AGA) neonates as the referent (25.2 μg/L), we observed lower levels in mothers of preterm AGA (21.9 μg/L), term small-for-gestational age (SGA) (20.3 μg/L), and preterm SGA neonates (21.7 μg/L). Results were largely unchanged after adjustment for prepreg-BMI. Leptin levels were higher in mothers who delivered large-for-gestational age (LGA) neonates, both preterm (33.6 μg/L) and term (29.1 μg/L), but the GMeans were markedly attenuated after adjustment for prepreg-BMI. Conclusion The association between BW/GA and maternal leptin levels after adjustment for prepreg-BMI may represent: 1) a residual effect of maternal adiposity that is not fully captured by BMI; and/or 2) variation in placental leptin levels entering the maternal circulation. In conclusion, mid-pregnancy maternal blood leptin levels may be an early indicator of fetal growth status.

22934578

PMC4004085

CDC Public Access