Maternal and neonatal leptin and leptin receptor polymorphisms associated with preterm birth

Leptin (LEP) and leptin receptor (LEPR) are suggested to play a role in female reproduction and especially in pregnancy Both LEP and LEPR are synthesized by the pregnant female and embryo. The link between genetic polymorphisms of LEP and LEPR and preterm birth (PTB) is unknown. We studied maternal and neonatal LEP and LEPR genetic polymorphisms and the association with PTB. Blood for DNA analysis was collected from Israeli mothers and from venous umbilical of their respected idiopathic preterm newborns (24–36 weeks, n = 102) and control term newborns (> 37 weeks, n = 158). Genotypes of maternal and neonatal LEP (rs7799039) and LEPR (rs1137101) polymorphisms were analyzed by restriction fragment length polymorphism analysis. Genotype-phenotype association was assayed using SPSS program. We found a significant independent increased risk of PTB for women and neonates bearing the homozygous AA form of LEP genotype; where women carrying AA LEP genotype had 2.53 fold ([CI] 1.367–4.685, p = 0.03) and 2.38 fold ([CI] 1.150–4.915, p = 0.019) increased risk for PTB compared to AG and GG genotypes, respectively. Neonates carrying the LEP AA genotype had a significant 2.8 fold increased risk for PTB compared to the AG genotype (CI11.040–7.577, p = 0.042). Maternal LEPR polymorphism was significantly associated with severe PTB; where women carrying the AA and AG genotypes had a significant 4.32 and 4.76 fold increased risk for severe PTB compared to women carrying the GG genotype (CI = 1.090–17.112 and 1.332–17.027, respectively p = 0.035). In conclusion: maternal and neonatal LEP and LEPR polymorphisms are significantly associated with increased risk for PTB.