Contraception in Hypertension

Hypertension increases the cardiovascular risk of oestrogen-containing methods and, to a lesser degree, some progestin-only methods. Many women with hypertension need contraception because of pre-eclampsia history, older age or antihypertensive medicines that are teratogenic. Selection depends on blood pressure level, control, vascular complications and other risk factors.

Assessment. Measure blood pressure on two occasions at rest, and classify: elevated 140/90 to 159/99, severe 160/100 or more, and controlled on treatment. Record vascular complications (ischaemic heart disease, stroke, retinopathy, nephropathy), diabetes, smoking, BMI, lipids, age, history of pre-eclampsia and medicines (ACE inhibitors, angiotensin receptor blockers and some others are teratogenic).

Hypertension in pregnancy. A history of high blood pressure in pregnancy with normal current pressure is category 2 for combined pills and category 1 for progestin-only methods and intrauterine devices.

When blood pressure cannot be measured. A history of hypertension where pressure cannot be evaluated makes combined pills category 3.

Effectiveness. Typical-use pregnancies per 100 women: implants 0.05, intrauterine devices 0.2 to 0.8, injectables 3, combined pills 8.

Eligibility.

Method comparison. Copper and levonorgestrel intrauterine devices and implants are the first choices; progestin-only pills are acceptable. Combined pills are not used in most hypertensive women. DMPA is used with caution in raised blood pressure because of the possible effect on arterial disease.

Antihypertensive medicines. ACE inhibitors, angiotensin receptor blockers and aldosterone antagonists are teratogenic and need reliable contraception. They do not interact with hormonal methods.

Special groups. Postpartum hypertension and pre-eclampsia: avoid combined methods; implants and progestin-only methods are safe. Diabetic women with hypertension and vascular disease follow the more restrictive categories.

Regimen lines.

• Copper T 380A: up to 12 years; levonorgestrel 52 mg device: 5 years; insertion within 12 days of the start of bleeding or at any time if reasonably not pregnant.

• Etonogestrel 68 mg rod: 3 years; levonorgestrel two 75 mg rods: 5 years or 3 years by system.

• Progestin-only pill: one tablet daily without a break; late window by type (traditional 3 hours, desogestrel 12 hours, drospirenone 24 hours); backup 2 days after a late or missed pill; drospirenone also has an antimineralocorticoid effect, so check potassium with ACE inhibitors, angiotensin receptor blockers or potassium-sparing diuretics.

• DMPA 150 mg intramuscularly every 13 weeks, up to 4 weeks late, or 104 mg subcutaneously every 13 weeks, up to 4 weeks late.

• Combined pill: only when blood pressure is normal, under 35 years, non-smoking and no vascular disease.

Blood pressure targets. Treat hypertension on its own merits; contraception does not substitute for control.

Follow up. Check blood pressure every visit for those on hormonal methods, and annually for others. Stop any combined pill if blood pressure rises to 140/90 or more.

Rising blood pressure on a combined pill. Stop the pill, switch to a progestin-only or non-hormonal method, and re-measure in 3 months.

Severe hypertension. Blood pressure 160/100 or more is a medical priority; contraception is chosen after stabilisation, and an intrauterine device or implant is preferred.

Stroke or ischaemic heart disease. Stop hormonal methods that raise thrombotic risk; implants and progestin-only methods are category 3 for continuation after stroke or ischaemic heart disease, and a copper device is preferred.

Red flags. Severe headache, chest pain, visual change, neurological deficit, breathlessness, blood pressure 180/110 or more.

Referral and escalation. Refer severe or resistant hypertension, vascular complications, pre-eclampsia and any cardiovascular event urgently.