During pregnancy, renal plasma flow changes. Which statement is accurate?

• A. Increases 60 to 80% by the second trimester, then decreases to 50% above pre-pregnancy values at term
• B. Remains unchanged throughout pregnancy
• C. Decreases by 20% during the second trimester
• D. Increases by 150% at term

Answer: (A)

Renal blood flow increases in pregnancy to support both mother and fetus. Hormonal changes cause dilation of renal vessels and expansion of plasma volume, so the kidneys receive more blood and the filtration rate rises as well. By the second trimester, renal plasma flow typically climbs about 60–80% above nonpregnant levels and remains elevated toward term, around 50% above pre-pregnancy values. That's why the statement describing a 60–80% increase by mid-pregnancy with about a 50% above-baseline level at term is accurate. The other options don’t fit this pattern: renal plasma flow does not stay unchanged, does not decrease by the second trimester, and does not reach a 150% increase by term.