Comparison of Umbilical Cord and Maternal Serum Levels of IGF-1, Leptin and Cortisol in Appropriate for Gestational Age and Small for Gestational Age Neonates

We aim to compare Insulin like Growth Factor (IGF-1), leptin, and cortisol concentrations in maternal and umbilical cord vein and to investigate the relationship between these values and fetal growth in appropriate for gestational age (AGA) and small for gestational age (SGA) neonates. Materials and Methods: In a case-control study, maternal and umbilical cord venous samples were collected from 25 SGA neonates and 25 AGA neonates in the obstetric ward at Hafez Hospital, Shiraz, Iran, between 2004 and 2005. Serum levels of IGF-1, leptin, and cortisol were measured by specific radioimmunoassay using commercial kits. Results: Mean maternal age was 25.38±5.22 years (range 17-38 yr) and mean gestational age was 37.92±1.79 weeks (range 34-41 weeks). Mean concentration of leptin and IGF-1 in cord blood was lower in SGA as compared with AGA neonates (p 0.012 and p 0.001, respectively). Maternal serum concentration of IGF-1 and cortisol were lower in SGA neonates (p 0.032 and p 0.011, respectively), however there was no significant difference in the concentration of maternal leptin levels between the two groups. A correlation was observed between the head circumference of neonate and maternal cortisol levels in the SGA group (p 0.01). Conclusion: Low IGF-1 and leptin concentrations in cord blood and low maternal serum concentration of IGF-1 and cortisol are associated with growth retardation in SGA as compared to AGA neonates. Also maternal cortisol level plays an important role in intrauterine brain development of SGA neonates.