Background: Plasma clearance of iohexol (Omnipaque) is well suited for determination of glomerular filtration rate (GFR) during pregnancy.
Objective: To settle guidelines for the use of iohexol clearance in diabetic pregnancy.
Study design: Prospective comparative.
Material and methods: Iohexol (5 ml) was injected intravenously and plasma concentrations determined by high pressure liquid chromatography after 180-240 min in 44 diabetic pregnant women.
Results: Iohexol clearance was normal in most cases of nephropathy or albuminuria. Iohexol clearance correlated negatively with blood pressure, S-Urate, and S-Creatinine. When S-Urate was < 232 mumol/l or S-Creatinine < 70 mumol/l, iohexol clearance was always normal (sensitivity = 1.0). When, in combination, S-Urate was > 345 mumol/l, and S-Creatinine > 70 mumol/l, iohexol clearance was always subnormal (sensitivity = specificity = Kappa index = 1.0).
Conclusions: In diabetic pregnancy, nephropathy or albuminuria cannot solely be used for selection of candidates for iohexol clearance determination. A S-Urate < 230 mumol/l (3.9 mg/dl) or S-Creatinine < 70 mumol/l (0.92 mg/dl) was reassuring for a normal GFR. We suggest iohexol clearance determinations in diabetic pregnancies when S-Urate is > 350 mumol/l (5.9 mg/dl) and/or S-Creatinine > 70 mumol/L.