How does serum creatinine change during pregnancy?

During pregnancy, serum creatinine decreases primarily due to renal vessel dilation and increased renal blood flow. As the body adapts to accommodate the growing fetus, there is a significant increase in plasma volume and glomerular filtration rate (GFR). This enhanced renal function, driven by hormonal changes such as increased levels of human chorionic gonadotropin (hCG) and progesterone, leads to an efficient clearance of creatinine from the bloodstream, resulting in lower serum levels.

The decrease in serum creatinine is an important physiological change during pregnancy and serves as an indicator of the kidneys’ increased efficiency. Clinicians often use serum creatinine levels to assess renal function; however, in pregnant individuals, it is vital to interpret these levels in the context of gestation because the normal range shifts downward.

Thus, the physiological adaptations during pregnancy directly influence serum creatinine by promoting lower levels through renal vascular changes and heightened filtration capacity.