Cord blood triglyceride and total cholesterol in preterm and term neonates: reference values and associated factors from the Japan Environment and Children's Study.

This study aimed to investigate the associations between cord serum total cholesterol (TC) and triglyceride (TG)levels and perinatal factors and determine the reference levels of cord blood TC and TG in Japanese neonates. This was a prospective birth cohort study using data from the Japan Environment and Children's Study, which included data on births from 2011 to 2014 in Japan. TC and TG levels were determined in cord blood samples. A total of 70,535 pairs of neonates (male: 36,001, female: 34,524) and mothers were included. The mean cord blood TC and TG levels were 72.2 mg/dL and 24.4 mg/dL, respectively. Multiple regression analyses revealed that gestational age and birth weight were significantly associated with cord blood TC (coefficient -2.35, 95% confidence interval [CI] -2.40 - -2.22 and coefficient 0.002, 95% CI 0.002-0.003, respectively) and TG (coefficient 3.09, 95% CI 3.01-3.17 and coefficient - 0.009, 95% CI - 0.009-0.008, respectively) levels. Mean cord blood TG and TC levels decreased over the preterm period; however, these parameters increased during the term. Furthermore, the mean cord blood TC and TG levels decreased over the entire range of birth weight categories.    Conclusion: Mean cord blood TG and TC levels decreased over the preterm period; however, these parameters increased during the term. Furthermore, the mean cord blood TC and TG levels decreased over the entire range of birth weight categories in Japanese newborns. Maternal complications such as maternal parity, HDP, PROM, maternal obesity and income level were associated with cord TC and TG levels. What is Known: • No studies have ascertained the reference levels of cord blood lipid levels in Japan. What is New: • Mean cord blood TG and TC levels decreased over the preterm period; however, these parameters increased during the term.