113. VASCULAR ENDOTHELIAL GROWTH FACTOR GENE POLYMORPHISMS IN PLACENTAL IMPAIRMENT AND SMALL FOR GESTATIONAL AGE BIRTH

Abstract

Impaired placental angiogenesis is implicated in the pathophysiology of small for gestational age (SGA) infants. Placental expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor, is reduced in SGA pregnancies. We aimed to evaluate the association of two single nucleotide polymorphisms (SNPs, VEGF-2578C/A and VEGF+936C/T) in VEGF gene which reduce VEGF expression, in SGA pregnancies andexamine their effects on first trimester placental VEGF expression. 3196 nulliparous pregnant women, their partners and babies were recruited in Adelaide and Auckland to a prospective multicentre cohort study (SCOPE Study). Amongst 2123 Caucasian women, 216 (11.9%) delivered a SGA infant defined as <10th customised centile. Uncomplicated Caucasian pregnancies served as controls (n = 1176). Uterine and umbilical artery Doppler velocimetry was performed at 20 weeks gestation. DNA extracted from peripheral blood from couples and cord blood from babies was genotyped using Sequenom MassARRAY. 74 first trimester placentae collected from elective terminations of pregnancy were genotyped for the same SNPs and the VEGF expression determined by RT-PCR. Neonatal VEGF+936 CT+TT genotypes associate with SGA (OR 1.6, 95%CI 1.1–2.3), lower birthweight (P = 0.005), customised birthweight centile (p=0.03), lower placental weight (P = 0.04) and an increased uterine artery resistance index (RI, P = 0.004). Maternal VEGF+936 CT+TT associate with bilateral notching of the uterine artery waveform (OR 1.4, 95%CI 1.0–1.8) and an increased umbilical artery RI (OR 1.5, 95%CI 1.1–2.1). VEGF+936 CT first trimester placentae have lower VEGF expression compared to CC (P = 0.045). Neonatal VEGF-2578 AA associates with bilateral uterine artery notching (OR 1.5, 95%CI 1.1–2.2) and increased umbilical artery RI (OR 1.6, 95%CI 1.0–2.6). Maternal VEGF-2578 CA+AA associate with increased umbilical artery RI (OR 1.5, 95%CI 1.0–2.2). VEGF polymorphisms reduce first trimester VEGF expression and associate with increased resistance in the placental circulation suggesting impaired placental function. VEGF+936 SNP confers increased risk for SGA.