The effect of hormonal contraceptive therapy on clinical laboratory parameters: a literature review

Hormonal contraceptives (HC) are widely used among women in reproductive ages. In this review, the effects of HCs on 91 routine chemistry tests, metabolic tests, and tests for liver function, hemostatic system, renal function, hormones, vitamins and minerals were evaluated. Test parameters were differently affected by the dosage, duration, composition of HCs and route of administration. Most studies concerned the effects of combined oral contraceptives (COC) on the metabolic, hemostatic and (sex) steroids test results. Although the majority of the effects were minor, a major increase was seen in angiotensinogen levels (90-375 %) and the concentrations of the binding proteins (SHBG [∼200 %], CBG [∼100 %], TBG [∼90 %], VDBP [∼30 %], and IGFBPs [∼40 %]). Also, there were significant changes in levels of their bound molecules (testosterone, T3, T4, cortisol, vitamin D, IGF1 and GH). Data about the effects of all kinds of HCs on all test results are limited and sometimes inconclusive due to the large variety in HC, administration routes and dosages. Still, it can be concluded that HC use in women mainly stimulates the liver production of binding proteins. All biochemical test results of women using HC should be assessed carefully and unexpected test results should be further evaluated for both methodological and pre-analytical reasons. As HCs change over time, future studies are needed to learn more about the effects of other types, routes and combinations of HCs on clinical chemistry tests.