Association between second- and third-trimester maternal lipid profiles and adverse perinatal outcomes among women with GDM and non-GDM: a retrospective cohort study
Authors: Shi Ping , Tang Jie , Yin Xiaoyan 
Published: May 2023

Abstract
Background
Lipid metabolism disorder during pregnancy has been reported in women with gestational diabetes mellitus (GDM). However, controversy remains regarding the relationship between maternal changes in lipid profiles and perinatal outcomes. This study investigated the association between maternal lipid levels and adverse perinatal outcomes in women with GDM and non-GDM.

Methods
In total, 1632 pregnant women with GDM and 9067 women with non-GDM who delivered between 2011–2021 were enrolled in this study. Serum samples were assayed for fasting total cholesterol (TC), triglyceride (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) levels during the second and third trimesters of pregnancy. Adjusted odds ratios (AOR) and 95% confidence intervals (95% CI) were calculated via multivariable logistic regression analysis to determine the association of lipid levels with perinatal outcomes.

Results
The serum TC, TG, LDL, and HDL levels in the third trimester were significantly higher than those in the second trimester (p < 0.001). Women with GDM had significantly higher levels of TC and TG in the second and third trimesters than those with non-GDM in the same trimesters, while HDL levels decreased in women with GDM (all p < 0.001). After adjusting for confounding factors by multivariate logistic regression, every mmol/L elevation in TG levels of women with GDM in second and third trimesters was associated with a higher risk of caesarean section (AOR = 1.241, 95% CI: 1.103–1.396, p < 0.001; AOR = 1.716, 95% CI: 1.556–1.921, p < 0.001), large for gestational age infants (LGA) (AOR = 1.419, 95% CI: 1.173–2.453, p = 0.001; AOR = 2.011, 95% CI: 1.673–2.735, p < 0.001), macrosomia (AOR = 1.220, 95% CI: 1.133–1.643, p = 0.005; AOR = 1.891, 95% CI: 1.322–2.519, p < 0.001), and neonatal unit admission (NUD; AOR = 1.781, 95% CI: 1.267–2.143, p < 0.001; AOR = 2.052, 95% CI: 1.811–2.432, p < 0.001) cesarean delivery (AOR = 1.423, 95% CI: 1.215–1.679, p < 0.001; AOR = 1.834, 95% CI: 1.453–2.019, p < 0.001), LGA (AOR = 1.593, 95% CI: 1.235–2.518, p = 0.004; AOR = 2.326, 95% CI: 1.728–2.914, p < 0.001), macrosomia (AOR = 1.346, 95% CI: 1.209–1.735, p = 0.006; AOR = 2.032, 95% CI: 1.503–2.627, p < 0.001), and neonatal unit admission (NUD) (AOR = 1.936, 95% CI: 1.453–2.546, p < 0.001; AOR = 1.993, 95% CI: 1.724–2.517, p < 0.001), which were higher than the relative risk of these perinatal outcomes in women with non-GDM. Additionally, every mmol/L increase in second and third-trimester HDL levels of women with GDM was associated with decreased risk of LGA(AOR = 0.421, 95% CI: 0.353–0.712, p = 0.007; AOR = 0.525, 95% CI: 0.319–0.832, p = 0.017) and NUD (AOR = 0.532, 95% CI: 0.327–0.773, p = 0.011; AOR = 0.319, 95% CI: 0.193–0.508, p < 0.001), and the risk reduction was not strong than that of women with GDM.

Conclusions
Among women with GDM, high maternal TG in the second and third trimesters was independently associated with an increased risk of cesarean section, LGA, macrosomia, and NUD. High maternal HDL during the second and third trimesters was significantly associated with decreased risk of LGA and NUD. These associations were stronger than those in women with non-GDM, suggesting the importance of monitoring second and third-trimester lipid profiles in improving clinical outcomes, especially in GDM pregnancies.