[A controlled study of the effect of oral contraceptives on blood pressure]

The possible hypertensive effect of oral contraceptives is a controversial issue. We studied 371 women, admitted to the family planning program of a state funded outpatient clinic, that were followed during 12 months. These women were divided in four groups: Group 1 was constituted by 98 women that used intrauterine devices. Group 2 by 98 women taking 30 micrograms of estrogen and 300 micrograms of progestogen. Group 3 by 83 women taking 35 micrograms of estrogen and 500 micrograms of progestogen and Group 4 by 92 puerperal women taking 30 micrograms of levonorgestrel, that after six months started to use an intrauterine device (n = 35) or the contraceptives of group 2 (n = 38) or group 3 (n = 19). Age, initial blood pressure and weight were similar in the four groups. There was no significant change in blood pressure after 6 or 12 months of follow up in any group. It is concluded that contraceptives containing estrogen concentrations up to 35 micrograms and progestogen concentrations between 300 and 500 micrograms do not induced changes in blood pressure.