A prospective controlled study of the effect on blood pressure of contraceptive preparations containing different types and dosages of progestogen

A prospective controlled study investigated the effects of oral contraceptives on blood pressure in 485 women who were between 17 and 46 years of age and had blood pressures of less than 140/90 mmHg at entry. The women were divided into seven groups depending on the chosen method of contraception: intrauterine device or barrier method (control group): ethinyl oestradiol 30 micrograms plus levonorgestrel 150 micrograms (Microgynon-30 or Ovranette); norethisterone 350 micrograms (Micronor); norgestrel 75 micrograms (Neogest); norethisterone oenanthate 200 mg intramuscularly every 2 months for the first 6 months, then every 3 months thereafter; ethinyl oestradiol 30 micrograms plus ethynodiol diacetate 2 mg (Conova-30); and ethynodiol diacetate 500 micrograms (Femulen). Blood pressures were measured every 3 months by the family planning clinic nurse under standardized conditions using an Elag-Köln automatic sphygmomanometer. After one year, blood pressure had risen significantly (P less than 0.05) in the 137 women taking ethinyl oestradiol plus levonorgestrel (mean systolic and diastolic rises 6.4 and 2.7 mmHg respectively) and in the 91 women taking ethinyl oestradiol plus ethynodiol diacetate (mean systolic and diastolic rises 6.2 and 3.0 mmHg respectively). The 94 women taking the progestogen-only preparations and the 143 women in the control group showed no increases in blood pressure. These data were confirmed after 2 years of follow-up.