Also, avoid prescribing combination OCs for women with a known thrombophilic defect. However, because screening for thrombophilia is not cost-effective, routinely evaluating candidates for combination contraception with testing for familial thrombophilic disorders is not recommended.
OBG Management: Does the dosage of estrogen determine the risk of VTE?
Kaunitz: That is the general assumption—that higher dosages of estrogen pose a greater risk—but we lack definitive evidence that OCs formulated with 20 μg of estrogen are any safer in this regard than those that contain 30 to 35 μg.7,9
There is some evidence that the progestin plays a role. OCs that contain desogestrel appear to carry almost twice the risk of VTE as those formulated with levonorgestrel or norgestimate.10
TABLE
How selected health conditions affect choice of contraceptive in women ≥35 years
| Condition | Recommendation* |
|---|---|
| Obesity | Avoid combination contraceptives (OCs, patch, and ring) |
| Smoking | |
| Diabetes | |
| Migraine | |
| Hypertension | |
| * Based on guidelines from the American College of Obstetricians and Gynecologists8 | |
| † Includes progestin-only OCs, progestin implants, depot medroxyprogesterone acetate, and copper and progestin-releasing intrauterine devices | |
Risk of MI, stroke may rise in some older women
OBG Management: Do perimenopausal women who take combination OCs face a heightened risk of MI or stroke?
Kaunitz: Yes, if they smoke or have hypertension. The reason: In women who use combination OCs, smoking and hypertension are synergistic risk factors for MI and stroke. That means perimenopausal women who smoke or have high blood pressure should avoid combination contraceptives.
Although it is limited, available evidence supports the safety of OCs in older women who do not smoke or have hypertension. One large case-control study from the United States found no increased risk of MI or stroke among this population when they used OCs containing less than 50 μg of ethinyl estradiol.11,12 However, this study included few women older than 35 years who used OCs and smoked or had hypertension.
A large, prospective study from Sweden that included 1,761 current OC users between 40 and 49 years of age found no increased risk of MI among former or current OC users.13 It also found that the initiation of OC use in women 30 years of age or older carried no higher risk of MI than did initiation at age 29 or younger.
Avoid OCs in older women who have diabetes
OBG Management: What about women 35 years of age or older who have diabetes? Is hormonal contraception appropriate for them?
Kaunitz: Both premenopausal and postmenopausal women who have diabetes have a higher risk of cardiovascular disease, so combination contraceptives are a bad idea when the woman has diabetes and is 35 years of age or older. OCs also should be avoided in women younger than 35 years who have diabetes, unless they are normotensive and free of nephropathy and other vascular disease. Intrauterine contraception and progestin-only formulations tend to be better options for diabetic women.
Avoid combination OCs in perimenopausal migraineurs
OBG Management: Isn’t there evidence that women who have migraine headaches have an elevated stroke risk? How does this affect their choice of contraceptive?
Kaunitz: One case-control study from a large US health maintenance organization found twice the risk of stroke among OC users who had migraines as among those who did not.12 However, this study did not distinguish between women who had migraines with aura and those who had migraines without aura.
Another study found an increased risk of stroke among OC users who had migraines with aura, but not among those who had migraines without aura.14
Accordingly, both the American College of Obstetricians and Gynecologists (ACOG) and the World Health Organization recommend that older women who experience migraines use progestin-only or intrauterine contraception.8,15
Does estrogen use increase the risk of breast cancer?
OBG Management: It’s a common assumption that hormonal contraceptives that contain estrogen increase the risk of breast cancer. Is that assumption backed by data?
Kaunitz: Long-term use of combination estrogen–progestin menopausal hormone therapy modestly increases the risk of breast cancer. Accordingly, many clinicians and women assume that use of hormonal contraception must likewise increase risk. In fact, the evidence does not indicate that combination OCs or progestin-only contraceptives increase the risk of breast cancer. However, studies to date have involved a relatively small number of women older than 45 years.
For example, a large cohort study from the United Kingdom that involved more than 1 million person-years of follow-up found no association between use of OCs and breast cancer, even among long-term users.16 Most cases of OC use in this study involved OCs formulated with 50 μg or more of ethinyl estradiol. However, this study did not indicate the age at which women used OCs.