What contraceptive methods are recommended for a woman over 35 years old who smokes?

Birth Control in Women Over 35 Who Smoke

Women over 35 years old who smoke must not use combined estrogen-progestin contraceptives (pills, patches, or vaginal rings) due to unacceptably high risks of myocardial infarction and stroke; instead, they should use progestin-only methods (pills, implants, or levonorgestrel IUD) or copper IUDs, which are equally effective and carry no increased cardiovascular risk. 1, 2

Absolute Contraindication to Combined Hormonal Contraception

• Estrogen-progestin contraception is formally contraindicated in all smokers over 35 years old, particularly those smoking more than 15 cigarettes per day 1
• This contraindication applies to all routes of administration: oral pills, transdermal patches, and vaginal rings 1, 3
• The relative risk of myocardial infarction reaches 12.5 in women smoking more than 20 cigarettes per day who use combined contraceptives 1, 3
• The combination of smoking and estrogen-containing contraceptives creates a synergistic thrombotic risk through increased PAI-1 (a fibrinolysis inhibitor) and altered hepatic estrogen metabolism 1, 3
• The vast majority of coronary and cerebral arterial events occur in women over 35-40 years old, especially in smokers 1

Recommended Safe Alternatives

Progestin-Only Methods (First-Line Options)

These methods can be used regardless of age and daily number of cigarettes smoked: 1

• Progestin-only pills (desogestrel 0.075 mg or norethindrone): No increased stroke or MI risk; relative risk for VTE = 0.90 (95% CI 0.57-1.45) 2, 3
• Levonorgestrel IUD: No thrombosis risk; pregnancy rate <1% per year; additional benefit of reducing menorrhagia 1, 2, 3
• Etonogestrel subdermal implant: No estrogen-related cardiovascular risks; >99% efficacy 2, 3
• Depot medroxyprogesterone acetate (DMPA): No increased stroke risk, though requires careful follow-up 2, 3

Non-Hormonal Option

• Copper IUD: No hormonal risks; >99% efficacy; appropriate alternative to all hormonal contraception 1, 2, 3

Clinical Decision Algorithm

Step 1: Assess smoking status

• Any smoking in women ≥35 years → Exclude combined hormonal contraception 1, 2

Step 2: Counsel on safe alternatives

• Offer progestin-only pills, levonorgestrel IUD, etonogestrel implant, or copper IUD as equally effective options 2, 3
• Emphasize that these methods carry no increased cardiovascular risk compared to combined methods 2, 3

Step 3: Address smoking cessation

• All patients who smoke should be encouraged and helped to quit at every visit 4
• Even if the patient quits smoking, combined hormonal contraception remains Category 2 (generally usable but requiring careful follow-up) in women >45 years due to age-related baseline cardiovascular risk 5, 2

Critical Pitfalls to Avoid

• Do not prescribe lower-dose estrogen formulations (20 µg ethinyl estradiol) as a "safer" alternative for smokers over 35; even ultra-low doses remain contraindicated 3, 4, 6
• Do not consider patches or vaginal rings as alternatives to oral pills; they share identical contraindications 1, 3
• Do not delay switching from combined to progestin-only methods if a patient over 35 continues or resumes smoking 3
• Do not assume that light smoking (<15 cigarettes/day) makes combined contraception acceptable; while the risk is lower, it remains a relative contraindication 1

Risk Context

• The attributable risk of cardiovascular death from combined oral contraceptives in smokers over 35 years is 19.4 per 100,000 users, with 85-97% of this risk due to the combined effects of smoking and estrogen 7
• This excess risk exceeds the risk of death from pregnancy in this age group 7
• In contrast, progestin-only and non-hormonal methods carry no increased cardiovascular mortality 2, 3

Duration of Contraception

• Continue contraception until menopause or age 50-55 years (median age of menopause is approximately 51 years) 5, 2
• No reliable laboratory tests confirm definitive loss of fertility; follicle-stimulating hormone levels are not accurate for this purpose 5
• Pregnancy in women of advanced reproductive age carries higher risks of maternal complications (hemorrhage, VTE, death) and fetal complications (spontaneous abortion, stillbirth, congenital anomalies) 5, 2