[Impact of synthetic sexual steroids on blood volume (author's transl)].

The isotope dilution technique was used to study the oestrogen component of "Deposiston", a long-acting contraceptive, and its effects on blood volume. Blood volume increased by about ten per cent within 15 days from administration of 3 mg of ethinyloestradiol-sulphonate (1 mg/week). Haematocrit was reduced, at the same time. This haemodynamic initial effect should be always taken into account for any assessment of biochemical parameters in response to hormonal contraception.