NORMAL VALUES OF URINARY ALBUMIN AND TOTAL PROTEIN EXCRETION DURING PREGNANCY

OBJECTIVE: Our purpose was to determine the normal 24-hour excretion v alues of urinary albumin and total protein in healthy pregnant women. STUDY DESIGN: We evaluated 270 healthy pregnant women less than or equ al to 35 years old without a history of diabetes, hypertension, pyelon ephritis, preeclampsia, or renal or connective tissue disease. Adequac y of 24-hour collection was determined by creatinine excretion. RESULT S: The mean protein excretion in 24 hours was 116.9 mg, upper 95% conf idence limit 259.4 mg. The mean albumin excretion in 24 hours was 11.8 mg, upper 95% confidence limit 28.7 mg. Both protein and albumin excr etion increased after 20 weeks of gestation. No patient had evidence o f microalbuminuria, defined as urinary albumin excretion >30 mg/L. CON CLUSION: These data support 260 mg per 24 hours of urinary protein and 29 mg per 24 hours of albumin as the upper limit of normal in pregnan cy. Albumin accounts for a small fraction of total urinary protein exc retion.