Maternal leptin across pregnancy in women with small-for-gestational-age infants.

Objective: We hypothesized that women with small-for-gestational-age (SGA) neonates would have lower concentrations of leptin compared to women with appropriately grown infants (AGA).
Study Design: This is a nested case-control study of normotensive nulliparous women. Cases (n = 28) delivered SGA < 10 percentile and controls (n = 77) delivered AGA. Maternal plasma leptin concentrations were compared at 18, 28, and 40 weeks' gestation via repeated measures.
Results: Maternal leptin concentrations at 18 weeks were correlated with prepregnancy BMI (r = 0.69, P < .0001) and early pregnancy waist circumference (r = 0.59, P < .0001). After adjustment for maternal body composition, leptin was lower across pregnancy in women with SGA compared to AGA neonates (13.6 vs 15.2 ng/mL at 18 weeks; 13.6 vs 17.3 ng/mL at 28 weeks; 16.6 vs 20.7 ng/mL at 40 weeks; P = .04).
Conclusion: Maternal leptin was correlated with maternal adiposity; however, after adjustment for body composition, leptin was lower across pregnancy in women with SGA.