The effect of the contraceptive pill on blood pressure: a randomized controlled trial of three progestogen-oestrogen combinations in Szeged, Hungary.

As part of an international multicentered investigation a double-blind comparative clinical trial was conducted at the Department of Obstetrics and Gynecology, University Medical School, Szeged, Hungary, in order to study the effect of different combined oral contraceptives on blood pressure. Healthy, normotensive women were randomly allocated to either of the following oral contraceptives: 250 micrograms levonorgestrel + 50 micrograms ethinyloestradiol (LN 250 + EE 50), 250 micrograms levonorgestrel + 30 micrograms ethinyloestradiol (LN 250 + EE 30), 1 mg norethisterone acetate + 50 micrograms ethinyloestradiol (NA 1 + EE 50). Standardized blood pressure measurements were carried out at admission and 3, 6, 9, and 12 months after admission. Blood pressure change from admission to subsequent visits was analysed in subjects who were seen by the same observer both at admission and the follow-up under consideration. The systolic blood pressure slightly but not significantly increased in groups LN 250 + EE 50 and NA 1 + EE 50, whereas the diastolic pressure showed a minimal decrease. In group LN 250 + EE 30 both systolic and diastolic blood pressure increased significantly (+5.58 and +3.20 mm Hg, respectively) at the 12-month follow-up. The study supports previous findings that combined oral contraceptive use is associated with a moderate rise in blood pressure. The progestogen-to-oestrogen ratio in the pill may be as important in this context as the dose of either component itself.