Cord blood lipid profile and associated factors: baseline data of a birth cohort study

The cord blood lipid profile may be associated with lifelong changes in the metabolic functions of the individual. The aim of the present study was for the first time in Iran to assess the cord blood lipid profile of neonates, as well as some of its environmental influencing factors. The subjects were 442 (218 boys and 224 girls) normal vaginal delivery newborns. Overall, 14.4% of neonates were preterm and the rest were full-term. In total, 9.2% (n = 35) of the full-term newborns were small-for-gestational-age (SGA), of which 16 had a ponderal index (PI) below the 10th percentile (SGA I) and 19 had a PI above the 10th percentile (SGA II), 5.5% (n = 21) were large-for-gestational-age (LGA), and the remainder were appropriate-for-gestational-age (AGA).Before becoming pregnant, 6.9% of mothers were underweight, 49.3% had normal body mass index (BMI), 39.4% were overweight and 4.4% were obese. Total and high-density lipoprotein cholesterol (HDL-C) in girls were significantly higher than in boys (80.3 +/- 33.3 and 31.1 +/- 9.9 vs. 73.3 +/- 23.1 and 28.8 +/- 8.7 mg/dL, respectively, P < 0.05). The mean apolipoprotein A (apoA) of neonates with underweight mothers was significantly lower, and the mean apoB level of those with overweight mothers was significantly higher than other neonates. The mean low-density lipoprotein cholesterol (LDL-C), HDL-C and apoA of the LGA newborns were significantly lower, and their apoB was significantly higher compared with AGA and SGA neonates. The SGA I neonates had significantly lower total cholesterol, LDL-C, HDL-C and apoA, as well as higher triglycerides, lipoprotein a and apoB than the SGA II group. The mean cord blood triglycerides of full-term neonates was significantly higher than preterm neonates (69.4 +/- 11.9 vs. 61.4 +/- 12.7 mg/dL, respectively, P = 0.04). A preconception maternal BMI of > or =25 kg/m(2) correlated significantly with the cord triglycerides (OR = 1.3, [95% CI 1.07, 1.5]) and with apoB (OR = 1.4, [95% CI 1.1, 1.5]). The BMI <18 of mothers before pregnancy correlated with low HDL-C (OR = 1.3, [95% CI 1.04, 1.7]). Birthweight correlated with high cord triglyceride level (SGA: OR = 1.4, [95% CI 1.1, 1.7]; LGA: OR = 1.6, [95% CI 1.3, 1.7] compared with AGA). These associations remained significant even after adjusting for the preconception BMI of mothers. Our findings reflect the possible interaction of environmental factors and fetal growth and the in utero lipid metabolism. Long-term longitudinal studies in different ethnicities would help to elucidate the relationship.