Maternal LDH levels may predict adverse pregnancy outcomes in women with severe preeclampsia

The elevated levels of LDH, particularly beyond 600 IU/L in the third trimester, were significantly linked to higher risks of adverse perinatal outcomes. The study findings were published online in the International Journal of Reproduction, Contraception, Obstetrics and Gynecology.

Preeclampsia is a potentially dangerous complication of pregnancy characterised by high blood pressure. It is a multisystem disorder that causes vascular endothelial damage and leads to leakage of LDH into maternal serum.

LDH is an intracellular enzyme found in almost all body tissues. It converts lactic acid to pyruvic acid, and an increased level indicates cellular death and leakage of the enzyme from the cell. Normal LDH levels vary from 200 to 400 IU/L. Pregnancy itself does not affect the LDH levels. When tissues are damaged by disease or injury, there is an increase in LDH levels in the blood, and as it is abundant in red blood cells, it can function as a marker for hemolysis.

Peter A. Awoyesuku, Department of Obstetrics and Gynaecology, Rivers State University Teaching Hospital, Port-Harcourt, Nigeria, and colleagues aimed to evaluate the serum LDH levels in severe preeclamptic women to detect any correlation with adverse pregnancy outcomes.

For this purpose, the researchers conducted a prospective cohort study comparing LDH levels of 68 severe preeclamptic women with 68 normotensives in the third trimester, matched for parity, age, and gestational age. To assess the maternal and neonatal outcomes, the preeclamptic women were followed up until delivery.

The study led to the following findings:

• Both groups were comparable in their characteristics. The mean LDH level for the severe preeclamptic group (717.40 IU/L) was higher than for the normotensive group (162.90 IU/L) and this was significant.
• Cesarean delivery was less likely when LDH was >600 compared to ≤600 (OR 0.31), indicating a potential protective effect.
• The likelihood of intrauterine growth restriction (OR 3.14), stillbirth (OR 7.06), intrauterine fetal death (OR 6.48), perinatal mortality (OR 4.84) and low birth weight <2500 gm (OR 3.77) were all significantly higher with LDH levels >600 IU/L.
  

"Maternal serum LDH levels were significantly elevated in pregnant women with severe preeclampsia compared to their normotensive counterparts," the researchers wrote, adding that, "elevated levels >600 IU/L in the third trimester was associated with adverse perinatal outcomes."

"Detection of increased lactate dehydrogenase levels should warrant close monitoring and appropriately-timed delivery to decrease the occurrence of serious adverse outcomes," they concluded.

Reference:

Awoyesuku PA, Ohaka C, Altraide BO, Amadi SC, Iwo-Amah RS, Ngeri B et al. Maternal serum lactate dehydrogenase level as a predictor of adverse pregnancy outcome in women with severe preeclampsia. Int J Reprod Contracept Obstet Gynecol 2024;13:201-10.