To investigate the correlation between lipid levels during gestation and the incidence rate of gestational diabetes mellitus (GDM) and macrosomia. Clinical records of 607 pregnant women with GDM (GDM group) who delivered in the Obstetrics Department of Fujian Maternal and Child Health Hospital from May to December 2018 and of 833 women with uncomplicated pregnancies (control group) were retrospectively analyzed. After delivery, the entire cohort was further grouped based on the weight of the neonates: women who delivered newborns with body mass <4 kg comprised the normal group (n = 1367), and pregnancies that resulted in delivery of neonates with body mass >4 kg were classified as the macrosomia group (n = 73). Fasting serum levels of triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and TG/HDL-C ratio were compared between the groups at the early (10-12 weeks), middle (24-28 weeks), and late (28 weeks-delivery) stages of pregnancy, and the correlation between the lipid indices and the rates of GDM and macrosomia were analyzed. There was a gradual increase in TC, TG, LDL-C, and TG/HDL-C levels with increasing gestational weeks in pregnant women. TG and TG/HDL-C levels were markedly higher, while HDL-C was lower in women with GDM compared with women of the same gestational age with uncomplicated pregnancies (p < 0.05). Lipid metabolism disorders exist in pregnant women with GDM at different gestational stages and are closely related to the higher incidence of macrosomia. TG, TG/HDL-C, and HDL-C in early and late pregnancy are independent risk factors for macrosomia in all trimesters, and TG/HDL-C ratio at different gestational stages has a good predictive value for macrosomia.