Impact of prenatal maternal LDH levels on adverse pregnancy outcomes in women with hypertensive disorders during pregnancy

Objective This study aimed to evaluate the association between maternal serum lactate dehydrogenase (LDH) levels and adverse pregnancy outcomes in women with hypertensive disorders of pregnancy (HDP), and to evaluate potential effect modification by metabolic risk factors. Materials and methods This study enrolled 627 pregnant women, including 206 with GH, 129 with PE, and 292 with severe PE. Serum LDH levels were measured before delivery, and pregnancy outcomes were extracted from electronic medical record. Multivariable logistic regression models were used to assess associations between LDH tertiles and adverse outcomes, adjusting for potential confounders. Stratified analyses were performed by HDP subtype, gestational diabetes mellitus (GDM) status, and pre-pregnancy body mass index (BMI). Results Compared with the lowest LDH tertile, the highest tertile was independently associated with significantly increased risks of preterm delivery (PD) (adjusted OR = 3.38; 95% CI: 2.14–5.34), low birth weight (LBW) (adjusted OR = 5.32; 95% CI: 3.27–8.65), and small-for-gestational-age infants (SGA) (adjusted OR = 2.42; 95% CI: 1.40–4.19). Subgroup analyses revealed distinct risk patterns: associations were significant only in women with PE or severe PE (not GH), and were modified by metabolic factors. Specifically, elevated LDH was associated with SGA in women with GDM or overweight/obesity (BMI ≥25 kg/m 2 ), whereas PD risk was confined to non-overweight/obesity, non-GDM women. Sensitivity analyses supported the robustness of these findings. Conclusion Elevated maternal LDH levels are independently associated with adverse pregnancy outcomes in HDP, with differential effects based on disease severity and metabolic profile. These results suggest that LDH may serve as a clinically useful biomarker for risk stratification, particularly in high-risk subgroups.