Objective:To investigate blood lipid profile and its changes of pregnant women,and to analyze if dyslipidemia occurred in those who suffered from gestational diabetes mellitus (GDM) or delivery of macrosomia. Methods: Based on the multi-center cohort study for reference intervals of gestational weight gain, total 516 singleton pregnant women were recruited from Danyang city, Jiangsu Province into the study for observation on serum lipid profiles during gestation. The general information of the subjects was collected and serum lipid [triglycerides(TG), total cholesterol(TC), low density lipoproten-cholesterol(LDL-C), and high density lipoprotein-cholesterol (HDL-C)] concentrations were tested in three trimesters of gestation. The complications during gestation and conditions of newborns were recorded as well. The lipid profiles during gestation were compared between women who delivered macrosomias and who did not, and between women with GDM and normal pregnancies. The lipid profiles were compared according to pregestational body mass index (BMI) levels in the first and third trimesters as well. Results: The serum lipid levels increased, the rate of HDL-C/TC decreased, and the rate of HDL-C/TC increased with progress of gestation in the investigated pregnant women (both P < 0.05). In same stage of pregnancy, there was little difference in lipid profiles between women who delivered macrosomias and who did not (both P > 0.05). The GDM women had higher serum TG level in first and second trimesters than normal pregnancies (both P < 0.05). Women with pregestational BMI≥24 kg/m2 were more likely to suffer from dyslipidemia in early pregnancy, and GDM morbidity of them was also higher than that of women with pregestational BMI<24 kg/m2. In our study, there was little difference in lipid profiles among different pregestational BMI levels in the third trimester. Conclusion: Hypertriglyceridemia in the first and second trimesters may be associated with higher risk of GDM. The women who are intended to conceive should keep a normal BMI to avoid dyslipidemia in early pregnancy.