Gestational Period-Specific Renal Functions: Evidence From a Large, Community-Based, Prospective Cohort in Rural Sri Lanka

Abstract

Renal functions in pregnancy undergo rapid changes, and the thresholds for normal values is a major research gap and are still debatable. We used a prospective cohort design with 2,259 first trimester pregnant women from Anuradhapura, Sri Lanka to estimate the gestational age-specific serum creatinine levels and compared with 2.012 nonpregnant women from the same geographical area. The mean (SD) sCr of the 2,012 nonpregnant women was 62.8(12.4) μmol/L, with a 97.5th percentile of 89.0 μmol/L. The mean (SD) sCr was 55.1, 52.7, 51.0, 47.2, and 49.3, while the 97.5th percentile for sCr was 72.4, 69.2, 69.3, 63.9, and 66.0 μmol/L, respectively, in the sample of pregnant women. In the first and second trimesters, the average sCr value was 84.7% and 76.4% of that of the nonpregnant group, respectively. The mean eGFR increased up to 129.4 mL/min/1.73 m2 in the 24th week of gestation. The analysis of cohort data clearly confirmed a significant reduction in sCr with advancing pregnancy (p<0 .001). This study confirms the previously reported secondary-data-based thresholds, and the clinical validation of the upper limits proposed needs to be evaluated with pregnancy and new-born outcomes.