Establishing reference ranges of serum lipid level during pregnancy and evaluating its association with perinatal outcomes: A cohort study

Objective To establish trimester-specific reference intervals (TSRIs) for blood lipid profiles in Chinese women and explore their associations with pregnancy outcomes. Methods Participants were women with singleton pregnancies aged 18-45 years without pre-existing chronic diseases who delivered from January 2018 to December 2018 from an ongoing cohort in Beijing, China. Baseline information and pregnancy outcomes were from the medical records. Blood lipid levels were measured at 7-13, 24-28, and 32-34 weeks of pregnancy. We estimated TSRIs for lipid profiles using an indirect Hoffmann method and evaluated their associations with pregnancy outcomes, including gestational diabetes, pregnancy-induced hypertension, macrosomia, low birth weight, large or small for gestational age, and preterm delivery. Results The established TSRIs were 3.21-5.38, 4.64-7.56, and 4.86-8.20 mmol/L for total cholesterol; 0.37-1.81, 1.14-3.49, and 1.61-4.63 mmol/L for triglycerides; 1.12-2.19, 1.33-2.49, and 1.24 2.31 mmol/L for high-density lipoprotein cholesterol; 1.33-2.98,1.97-4.36, and 2.02-4.92 mmol/L for low-density lipoprotein cholesterol from first trimeseter to third trimester, respectively. Both higher and lower levels of lipid profiles than TSRIs were associated with adverse pregnancy outcomes. Conclusion We suggested TSRIs for blood lipid levels in a Chinese population. Inappropriate lipid levels were associated with adverse pregnancy outcomes.