Figure 3:

Effective renal plasma flow, glomerular filtration rate, and creatinine changes during pregnancy.

Figure illustrates the changes in effective renal plasma flow, glomerular filtration rate, and serum creatinine concentrations during normal pregnancy the renal blood flow rises to about 70–80% from its baseline value at 20–22 weeks of gestation, and then falls to about 60–70% above pre-pregnancy levels towards the end of pregnancy, while the glomerular filtration rate (GFR) rises in parallel to about 40–50% of its baseline values at 20–22 weeks, then continues to increase through most of the third trimester, up to 36–38 weeks of gestation, when it declines steadily until the time of delivery.

A 2019 systematic review of serum creatinine concentrations during pregnancy from 49 studies that measured over 4,000 serum creatinine concentrations in healthy pregnant women demonstrated that the mean values for serum creatinine in the first, second, and third trimesters were 16, 23, and 20% lower when compared to baseline values in nonpregnant adults (as shown in figure above).