Comparison of Maternal-Fetal Acid-Base Metabolism in Pregnant Patients with Severe Preeclampsia without and with Obesity
Juan Gustavo Vázquez-Rodríguez *
Intensive Care Unit, High Specialty Medical Unit, Gynecology and Obstetrics Hospital No. 3. National Medical Center “La Raza”, Mexican Institute of Social Security, Mexico City, Mexico.
Angélica Bustos Otero
Intensive Care Unit, High Specialty Medical Unit, Gynecology and Obstetrics Hospital No. 3. National Medical Center “La Raza”, Mexican Institute of Social Security, Mexico City, Mexico.
Francisco Alonso Díaz Aguilar
Intensive Care Unit, High Specialty Medical Unit, Gynecology and Obstetrics Hospital No. 3. National Medical Center “La Raza”, Mexican Institute of Social Security, Mexico City, Mexico.
*Author to whom correspondence should be addressed.
Abstract
Aims: To identify and compare maternal and fetal acid-base metabolism in pregnant patients with severe preeclampsia (SP) without and with obesity.
Study Design: Cross-sectional, descriptive and analytical study.
Place and Duration of Study: Intensive Care Unit (ICU) of the High Specialty Medical Unit, Gynecology and Obstetrics Hospital No. 3. National Medical Center "La Raza", Mexican Institute of Social Security, Mexico City, between January 1 and December 31, 2024.
Methodology: This study was conducted in pregnant patients with SP in ICU: 36 patients with normal Body Mass Index ((BMI) <25 and 31 patients with obesity (BMI >30). Acid-base metabolism was compared with maternal arterial blood gas measurements upon admission to the ICU and umbilical artery measurements during cesarean section. Statistical analysis: descriptive statistics, Mann-Whitney U test, and chi-square test. A value P <.05 was considered significant. SPSS™ version 22 statistical software was used.
Results: Maternal arterial blood gas: negative values for the BE ecf and BE (B) were found in both groups, but with a significant intergroup difference only for the BE ecf (BE ecf normal BMI -6.08±-5.38 vs obesity -9.41±-3.46 mmol/L, P=.01: BE (B) normal BMI -6.62±-2.68 vs obesity -8.11±-3.11, P=.68). Comparison of the other blood gas parameters (pH, PaCO2, Lactate, Bicarbonate, Standard bicarbonate) showed no significant differences. The findings were interpreted as a state of compensated metabolic acidosis in both groups, but with statistical significance of the BE ecf in favor of patients with obesity.
Umbilical artery blood gas: negative values for the BE ecf and BE (B) were documented without significant intergroup differences (BE ecf normal IBM -7.37±-3.94 vs obesity -8.02±-3.76 mmol/L, P=.50; BE (B) normal BMI -6.48±-4.4 vs obesity -7.78±3.93 mmol/L, P=.21). Comparison of the other blood gas parameters (pH, PaCO2, Lactate, Bicarbonate, Standard bicarbonate) showed no significant differences. The findings were interpreted as a state of compensated metabolic acidosis in both groups, but without intergroup statistical significance.
Conclusion: The findings were interpreted as a state of compensated maternal and fetal metabolic acidosis in both groups, but with statistical significance of the BE ecf in favor of mothers with obesity.
Keywords: Maternal acid-base metabolism, fetal acid-base metabolism, maternal arterial blood gas analysis, umbilical arterial blood gas analysis, severe preeclampsia, pregnancy