A decrease in total plasma protein during pregnancy is primarily due to what?

A decrease in total plasma protein during pregnancy is primarily due to what?

• A. Increased synthesis
• B. Hemodilution
• C. Increased filtration
• D. Dehydration

Answer: (B)

Hemodilution from expanded plasma volume is the key factor. During pregnancy, the body retains more fluid, expanding the intravascular volume by a substantial amount. This increases the total volume in which plasma proteins are dissolved, so the concentration of plasma proteins falls even if the liver’s production of proteins (like albumin) rises somewhat. In short, the volume increase outpaces any rise in protein synthesis, producing a lower measured plasma protein level. Dehydration would raise, not lower, plasma protein concentration, and increased filtration or reduced synthesis aren’t the primary drivers of this dilutional effect.

Hemodilution from expanded plasma volume is the key factor. During pregnancy, the body retains more fluid, expanding the intravascular volume by a substantial amount. This increases the total volume in which plasma proteins are dissolved, so the concentration of plasma proteins falls even if the liver’s production of proteins (like albumin) rises somewhat. In short, the volume increase outpaces any rise in protein synthesis, producing a lower measured plasma protein level. Dehydration would raise, not lower, plasma protein concentration, and increased filtration or reduced synthesis aren’t the primary drivers of this dilutional effect.