[Electrolyte studies of the amniotic fluid]

Area of Science:

• Obstetrics and Gynecology
• Maternal-Fetal Medicine
• Neonatal Physiology

Background:

• Electrolytes in amniotic fluid are crucial for fetal homeostasis.
• Disturbances in amniotic fluid electrolytes can lead to fetal demise.
• Limited data exists on electrolyte reference values and their changes in pathological pregnancy states.

Purpose of the Study:

• To establish reference values for sodium, potassium, chloride, and calcium in amniotic fluid.
• To investigate electrolyte concentration changes in pre-pathological and pathological pregnancy conditions.
• To understand the role of fetal kidneys and placental function in maintaining fetal homeostasis.

Main Methods:

• Investigated 135 pregnant women with pregnancy complications and 200 controls.
• Analyzed amniotic fluid samples for sodium, potassium, chloride, and calcium concentrations.
• Compared electrolyte levels across various pregnancy states, including preterm/prolonged pregnancy, fetal asphyxia, and pre-eclampsia.

Main Results:

• A stable state of electrolyte concentrations was observed throughout normal pregnancy.
• No significant electrolyte changes were found in preterm/prolonged pregnancy or fetal asphyxia.
• A highly significant decrease in calcium ion concentration was detected in amniotic fluid of women with pre-eclampsia.

Conclusions:

• Amniotic fluid electrolyte concentrations remain stable during normal pregnancy.
• Pre-eclampsia is associated with a significant reduction in amniotic fluid calcium.
• Fetal kidneys, in conjunction with the placenta, are key regulators of fetal homeostasis.