Background One of the most prevalent medical issues observed during pregnancy is hypertension. Hypertensive disorders of pregnancy (HDP) and their consequences affect around 5-10% of all pregnancies globally. Preeclampsia is caused by endothelial dysfunction, which causes widespread endothelial leakage and contributes to potentially fatal consequences, such as eclampsia, placental abruption, disseminated intravascular coagulation (DIC), severe renal failure, pulmonary edema, and hepatocellular necrosis. As a result, looking for predictive markers for at-risk pregnancies that can suggest poor maternal or fetal outcomes is critical. Elevated levels of lactate dehydrogenase (LDH), as a sign of cellular damage and dysfunction, can be utilized as a biochemical marker in pregnancy-induced hypertension (PIH) as it represents the severity of the disease, and the occurrence of problems, and has also been demonstrated to co-relate with fetomaternal outcomes. Methodology A total of 230 singleton pregnant women of 28-40 weeks of gestational age were enrolled in this study. All women were divided into two groups - normotensive and preeclamptic-eclamptic groups; the second group was further divided into mild preeclampsia, severe preeclampsia, and eclampsia, based on blood pressure and the presence of proteinuria. Serum lactate dehydrogenase levels were measured in both groups and correlated with their fetomaternal outcome. Results Mean serum lactate dehydrogenase (LDH) level in eclamptic women was 1515.86 ± 754, in severely preeclamptic women was 932.2 ± 448, mild preeclamptic women were 580.5±213, while in normotensive women mean LDH level was 378.6 ± 124. The difference between normotensive and preeclamptic-eclamptic women was statistically significant (p < 0.001). The complications in the preeclamptic-eclamptic group were increased significantly in women with LDH > 800 IU/L, 600-800 IU/L compared to those who had < 600 IU/L LDH levels. Conclusions Serum LDH levels were significantly higher in women of preeclamptic-eclamptic group compared to the normotensive pregnant women. Higher LDH levels were positively correlated with disease severity and maternal complications like placental abruption, hemolysis elevated liver enzymes low platelet count (HELLP), disseminated intravascular coagulation (DIC), acute renal failure, intracranial hemorrhage, pulmonary edema, and maternal death and for fetal complications like preterm, intrauterine growth restriction (IUGR), APGAR at 1 minute < 7, APGAR at 5 minutes < 7, low birth weight (LBW), neonatal intensive care unit (NICU) admission and intrauterine fetal death (IUFD).