Abstract
BACKGROUND: Maternal glucose and lipid levels are known to influence fetal growth. However, data on how maternal lipid profiles affect birth size in women with gestational diabetes (GDM) compared with those without GDM are scarce. METHODS: This retrospective study included 10,490 women with singleton pregnancies (2351 with GDM and 8139 without GDM) between December 2016 and July 2022. Maternal serum levels of total cholesterol (TC), triglycerides (TGs), low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol were measured at 28-42 weeks of gestation. Maternal glucose levels were determined using the 2-h oral glucose tolerance test. The neonatal birth weight was obtained at delivery and standardized as the birth weight z score according to the INTERGROWTH-21st standards. RESULTS: Compared with women without GDM, those with GDM presented increased mean TG levels and decreased levels of TC, HDL cholesterol, and LDL cholesterol. TG levels were positively associated with birth weight in both the GDM and non-GDM groups, whereas TC, HDL cholesterol, and LDL cholesterol levels were mildly negatively correlated with birth weight. In the GDM group, an increase of 1 mmol/L in maternal TGs correlated with a 28.4 g increase in birth weight (95% CI: 17.8 to 39.1), whereas increases of 1 mmol/L in TC (-19.2 g; 95% CI: -31.9 to -6.5), HDL cholesterol (-120.7 g; 95% CI: -164.8 to -76.6), and LDL cholesterol (-22.2 g; 95% CI: -40.4 to -4) were associated with a decrease in birth weight. Compared with women with GDM with TG levels ≤ the 10th percentile, those with TG levels ≥ the 90th percentile had increased risks of large-for-gestational-age offspring (adjusted OR: 3.09; 95% CI: 1.51-6.30) and macrosomia (adjusted OR: 4.04; 95% CI: 1.37-11.93); this risk was stronger than that in women without GDM. CONCLUSIONS: This study provides evidence of a significant association between maternal lipid levels during late pregnancy and offspring birth size. However, the observational nature of the study limits the ability to establish causal relationships regarding the direct impact of lipid levels on birth size. Additionally, the influence of maternal lipid profiles is disproportionately greater in women with GDM than in women without GDM.