[The effect of oral contraceptives on the intraindividual variation of clinico-biochemical parameters]

The effects of oral contraceptives on the average biological intra-individual variation of 22 clinical-biochemical analytes were investigated. There was no effect for sodium, chloride, potassium, calcium, urea, creatinine, uric acid, HDL-cholesterol, triglycerides, thyroxin, triiodothyronine, ASAT, ALAT, gamma-GT, AAP, ChE in serum. Whereas the average biological intra-individual variation of total protein, albumin, cholesterol, hemoglobin and amylase were significantly higher in the group of women taking oral contraceptives. For these analytes the use of oral contraceptives must be considered in establishing decision making criteria for longitudinal monitoring.