Under the combined action of a variety of hormones during pregnancy, the blood lipid level of pregnant women will remain in a high balance during the entire pregnancy, which can not only meet the fetus's needs for nutrients, but also store raw materials for postpartum breastfeeding . The level of TG starts to increase at the 9th week of pregnancy, while TC and LDL-C decrease. At the 12th week of pregnancy, HDL-C and PL continue to increase, especially for pregnant women with GDM . At present, domestic and foreign studies have confirmed that the blood glucose level of pregnant women with GDM will cause the newborn to grow too quickly in the uterus, and even large babies may appear . Research by Hashimoto et al. also showed that there is a linear relationship between GA and adverse pregnancy outcomes . Although the blood glucose level of pregnant women with GDM can be controlled at a reasonable level through drugs, the incidence of macrosomia has not been reduced, which proves that the incidence of macrosomia is related to the blood lipid level .
One of the recognized pathogenic factors of GDM is insulin resistance, and chronic inflammation can aggravate insulin resistance [23–24]. Domestic and foreign studies have shown that the expression levels of TLR4, NF-κ B and inflammatory factors (such as TNF-α, IL-6 and CRP) in placental tissue or peripheral blood of GDM pregnant women are higher than those in normal pregnant women [25–26]. Giannoukakis et al. used IκB to inhibit the expression of NF-κB and reduce the damage of inflammatory factors to pancreatic β cells . These studies prove that TLR4, NF-κB, and inflammatory factors are closely related to GDM.
In this study, the blood lipid levels (TC, TG, HDL-C, LDL-C), the blood glucose levels (FPG, HbAlc, GA), and inflammatory factor TLR4 expression levels in two groups were monitored. The results showed that the levels of TG, FPG, HbA1c, GA in pregnant women, TLR4 in cord blood of newborn, and the relative expression of TLR4 protein and TLR4mRNA in the placenta in the research group were significantly higher than those in the control group (P<0.05), and the level of HDL-C was significantly lower than that in the control group (P<0.05). The weight of newborns was positively correlated with the levels of TG, FPG, HbA1c, and GA of pregnant women in the research group, the levels of TLR4 in the umbilical cord blood of pregnant women, and the relative expression of TLR4 protein and TLR4mRNA in the placenta, and negatively correlated with the levels of HDL-C, but there is no correlation with TC and LDL-C was found. The reason may be that the high levels of blood glucose and blood lipid in pregnant women with GDM will directly enter the newborn’s body through the umbilical cord, causing the newborn’s blood glucose to rise. The stimulation of pancreatic islet cells causes the newborn’s hyperinsulinemia. When glucose and fat continue to accumulate in the newborn’s body, excessive growth even macrosomia phenomenon will be easy to occur.