Relationship between umbilical cord blood leptin and fetal intrauterine growth

Objective To explore the role of umbilical cord blood leptin in intrauterine growth so as to provide evidence for early intervention for metabolic diseases. Methods Two hundred and sixty-six healthy newborns (140 males, 126 females, gestational age>37 weeks) and their healthy mothers were enrolled in this study. Birth weight, birth length, head circumference, and ponderal index were measured before the neonates were assigned to low birth weight (LBW), normal birth weight (NBW) and high birth weight (HBW) groups. The level of leptin in the umbilical cord plasma was assayed by radioimmunoassay (RIA). Student's t test, Pearson correlation analysis and multi factor line regression were used for data analysis. Results Leptin was significantly decreased in the LBW group ((7±5) μg/L) and increased in the HBW group ((15±7) μg/L) when compared with the NBW group ((9±5) μg/L) (t values were 3.216 and -4.026, respectively; both P<0.05). Leptin in female neonates ((11±6) μg/L) was significantly higher than that in male neonates ((8±5) μg/L) (t=-3.800, P<0.01). In Pearson correlation analysis, leptin was positively correlated with birth weight, height, body mass index (BMI) and placental weight (r values were 0.391, 0.280, 0.361 and 0.323, respectively; all P<0.01). After adjustment for maternal age, pre-pregnancy BMI, newborn gender and gestational age, leptin showed a liner relationship with birth weight. Conclusions The level of leptin in umbilical cord blood may be associated with birth weight and could be used as an indicator of intrauterine growth. Key words: Leptin; Fetals; Intrauterine growth