Maternal and Fetal Acid-base Metabolism in Severe Preeclampsia: An Analysis from the Experience of a Single Center of High Specialty in Mexico City

Abstract

Background: Alterations in maternal and fetal acid-base metabolism in pregnant patients with severe preeclampsia (SP) have been a topic of international research for many years Objective: The present study analyze the data on maternal and fetal acid-base metabolism in pregnant patients with SP and fluid therapy as an alternative therapy. Methods: Data from all cross-sectional analytical studies conducted at a single center of high specialty in Mexico City were reviewed. Clinical data, maternal arterial blood gas parameters performed upon admission to the intensive care unit (ICU) and umbilical artery blood gas at the time of delivery were studied. The results were compared with those of other studies considered classic in the international literature. Results: Four cross-sectional analytical studies were conducted (2021-2025) involving 270 pregnant patients with SP in the ICU. A state of maternal and fetal metabolic acidosis was found in all the studies reviewed. The Wheeler criterion (initial BE more negative than -8.0 mmol/L on maternal arterial blood gas) which has been identified as a predictor of maternal and fetal complications in SP was present in a range of 6% to 38.79% (mean 27.94%). Interpretation of the findings suggests that SP presents with signs and symptoms like shock with arterial hypertension, true or relative hypovolemia and maternal and fetal tissue hypoperfusion (metabolic acidosis). Therefore, fluid management may be a strategic option. Data from studies conducted at the host hospital on pregnant patients with SP who were treated with crystalloid solutions or albumin replacement were reviewed. It was found that restricted administration before delivery did not alter maternal or fetal metabolic acidosis data. Findings are limited to a single-center observational study. Conclusion: Studies showed maternal and fetal metabolic acidosis in SP. Fluid replacement is proposed prior to antihypertensive therapy or simultaneously, with monitoring of maternal and umbilical artery blood gases during delivery. Cause-and-effect protocols are needed to document the benefit to acid-base metabolism.