Electrolytes concentration patterns in the three trimesters of pregnancy

Abstract

The physiologic adaptations of the pregnant woman involve the renal, cardiovascular and other systems of the body. This study aimed at evaluating electrolyte concentrations in the three trimesters of pregnancy. Blood samples were collected by aseptic techniques and the concentrations of electrolytes were determined using standard laboratory methods such as titration for chloride and bicarbonate and flame photometry for sodium and potassium. Eighty healthy volunteers consisting of 20 non-pregnant control and 20 pregnant women in each of the three trimesters of pregnancy participated in the study. The sodium concentrations in mmol/L were 135.91 ± 3.00, 136.42 ± 3.11, 135.70 ± 2.90, and 136.30 ± 2.52, for control, first trimester, second trimester and third trimester subjects respectively. The potassium concentrations in mmol/L were 3.51 ± 0.18, 3.49 ± 0.11, 3.53 ± 0.20, and 3.50 ± 0.21, for control, first trimester, second trimester and third trimester subjects respectively. The chloride concentrations in mmol/L were 103.50± 3.21, 103.60± 2.92, 104.70 ± 3.10, and 105.0 ± 3.02, for control, first trimester, second trimester and third trimester subjects respectively. The Bicarbonate concentrations in mmol/L were 25.75 ± 1.51, 26.11 ± 1.17, 25.69 ± 1.72, and 26.10 ± 1.13, for control, first trimester, second trimester and third trimester subjects respectively. This study revealed that the electrolytes sodium, potassium, chloride and bicarbonate remained unchanged (p>0.05) as pregnancy advanced. This suggests that the kidneys are well adapted to the handling of electrolytes during pregnancy.
© 2015 International Formulae Group. All rights reserved.

Keywords: Sodium, potassium, bicarbonate, chloride, kidney