How does birth control affect Hypertension?

From the Guidelines

Birth control can increase the risk of hypertension, with studies showing a small but significant increase in blood pressure among users of combined oral contraceptives (COCs) 1.

Key Points

• The risk of developing hypertension is estimated to be around 5% among COC users 1.
• The increase in blood pressure is generally reversible, with blood pressure returning to pre-treatment levels within 3 months of discontinuing COCs 1.
• Progestin-only pills, such as norethindrone 0.35mg daily, or intrauterine devices (IUDs) containing levonorgestrel 52mg, are generally considered safer alternatives for women with hypertension 1.
• Women with well-controlled hypertension may be eligible for COCs, but their blood pressure should be monitored closely, ideally every 3-6 months 1.
• The estrogen component of COCs is thought to be primarily responsible for blood pressure changes, with progestins potentially enhancing the effects of estrogen on blood pressure 1.
• The risk of hypertension associated with COC use is dose-dependent, with higher doses of estrogen associated with a greater risk of hypertension 1.

Recommendations

• Women with severe hypertension (systolic pressure ≥160 mmHg or diastolic pressure ≥100 mmHg) should not use COCs 1.
• Women with less severe hypertension (systolic pressure 140-159 mmHg or diastolic pressure 90-99 mmHg) should use COCs with caution and have their blood pressure monitored closely 1.
• Progestin-only pills or IUDs may be a safer alternative for women with hypertension 1.

From the FDA Drug Label

Oral contraceptives may compound the effects of well-known risk factors, such as hypertension, diabetes, hyperlipidemias, age and obesity An increase in blood pressure has been reported in women taking oral contraceptives and this increase is more likely in older oral contraceptive users and with continued use Women with a history of hypertension or hypertension-related diseases, or renal disease should be encouraged to use another method of contraception If women elect to use oral contraceptives, they should be monitored closely and if significant elevation of blood pressure occurs, oral contraceptives should be discontinued

Birth control can increase blood pressure in some women, particularly those with a history of hypertension or hypertension-related diseases. The risk of hypertension is more likely in older oral contraceptive users and with continued use. Monitoring of blood pressure is recommended for women taking oral contraceptives, especially those with a history of hypertension. If significant elevation of blood pressure occurs, oral contraceptives should be discontinued 2, 2.

From the Research

Effects of Birth Control on Hypertension

• The use of combined oral contraceptives (COCs) has been associated with an increased risk of cardiovascular events, including stroke and acute myocardial infarction (AMI), in women with hypertension 3.
• Women who use COCs and have hypertension are at a higher risk for cardiovascular events than those who do not use COCs 3.
• The risk of cardiovascular events associated with COC use is higher in women who do not have their blood pressure measured before initiating COC use 3.
• Progestogen-only pills (POPs) may be a safer alternative for women with hypertension, as they have been shown to have no significant association with high blood pressure 4.

Cardiovascular Risk Factors

• The use of COCs is associated with an increased risk of venous thromboembolism, particularly in the first year of use 5.
• Women who use COCs and are older than 35 years, or who are current smokers, are at a higher risk for cardiovascular events 5.
• The presence of poorly controlled hypertension is associated with an increased risk of myocardial infarction and ischemic stroke in women who use COCs 5.
• Discontinuation of COCs may improve blood pressure control in women with hypertension 5.

Mechanisms of Birth Control-Induced Hypertension

• The estrogenic component of COCs appears to be the more important factor in producing abnormalities in the renin system, which may contribute to the development of hypertension 6.
• The use of COCs can lead to changes in the renin-angiotensin-aldosterone system, including an increase in plasma renin substrate concentration, which may be associated with increases in plasma renin activity and aldosterone excretion 6.
• The mechanisms of birth control-induced hypertension are not entirely clear, but may involve both volume and vasoconstrictor components mediated by the sodium-retaining effects of estrogen 6.

Specific Birth Control Formulations

• A contraceptive containing drospirenone and ethinylestradiol may have a positive or neutral effect on neurohumoral activation and metabolic homeostasis in hypertensive women 7.
• The use of a contraceptive containing 20 mcg of ethinyl estradiol and 3 mg of drospirenone was found to cause no significant changes in clinical and autonomic parameters, metabolic variables, and neurohumoral axis in hypertensive women 7.