Objective: To explore the serum lipids levels in healthy pregnant women, and to establish the reference intervals of serum lipids in middle and late pregnancy.
Methods: Triglyceride (TG), total cholesterol (TCH), high density lipoprotein (HDL), low density lipoprotein (LDL), apo-lipoprotein-A(APO-A) and apo-lipoprotein-B (APO-B) were measured in 3 200 pregnant women and 3 200 healthy women of childbearing age(the control group) from January 2014 to Febuary 2015 in Obstetrics and Gynecology Hospital of Fudan University. In the healthy pregnant women, serum lipids were measured at 14-20, 24-28 and 37-40 gestational weeks, respectively. All the parameters were detected by Hitachi 7180 automatic biochemical analyzer. The test results were calculated and determined by the C28-A3 standard of the National Clinical and Laboratory Standards Institute. And the normal reference intervals of serum lipids in middle and late pregnancy were defined as 2.5%-97.5%.
Results: (1) The levels of TG, TCH, HDL, LDL, APO-A and APO-B in the control group were 0.8, 4.2, 1.0, 2.7 mmol/L and 1.1, 0.8 g/L, respectively. The levels of TG, TCH, HDL, LDL, APO-A and APO-B in middle and late pregnancy were significantly higher than those in the control group (P<0.05). (2) The serum lipids levels at 14-20, 24-28 and 37-40 gestational weeks in healthy pregnant women were compared with the control group as following. The TG levels were 1.9, 3.8 and 4.4 folds of the control group; the TCH levels were 1.1, 1.5 and 1.5 folds of the control group; the HDL levels were 1.2, 1.6 and 1.5 folds of the control group; the LDL levels were 1.1, 1.4 and 1.4 folds of the control group; the APO-A levels were 1.3, 1.4 and 1.5 folds of the control group; and the APO-B levels were 1.1, 1.5 and 1.5 fold of the control group respectively. The TG level was the most increased, and it increased gradually with gestational age (P<0.01). (3) The median of LDL to HDL cholesterol ratio in the healthy pregnancy group at 14-20, 24-28 and 37-40 gestational weeks were 2.7, 2.5, 2.6, respectively, which were significantly lower than that of the control group (2.8; P<0.05). (4) Reference intervals of serum lipids at 14-20, 24-28 and 37-40 gestational weeks in healthy pregnant women were as following. The TG levels were 0.7-3.9, 1.7-6.3 and 1.6-8.1 mmol/L, respectively; the TCH were 3.3-6.9, 4.3-8.3, 4.3-8.7 mmol/L, respectively; the HDL were 0.8-1.8, 1.0-2.1 and 1.0-2.1 mmol/L, respectively; the LDL were 2.1-4.5, 2.7-5.1 and 2.6-5.2 mmol/L, respectively; the APO-A were 1.1-1.8, 1.2-1.9 and 1.1-2.4 g/L, respectively; and the APO-B were 0.6-1.4, 0.9-1.8 and 0.8-2.1 g/L, respectively. The LDL/HDL ratios were 2.3-3.1, 2.2-2.9 and 2.1-3.0, respectively.
Conclusions: Serum lipids increased physiologically with gestational age in middle and late pregnancy. The establishment of reference intervals for serum lipids in pregnancy will help to distinguish abnormal serum lipid levels in middle and late pregnancy.