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This installment of our Complex Contraceptives series examines contraception considerations for patients with high-blood pressure.
Hypertension is a primary contributor to cardiovascular disease (CVD), which is a major cause of death in women. Traditionally defined as an average blood pressure of at least 140/90 mm Hg or use of antihypertensive medication, hypertension affects about 30% of US adults aged 18 or older.1 While the 140/90 mm Hg cutoff is used in the 2004 Joint National Commission (JNC) report on hypertension, more recently, the American College of Cardiology and the American Heart Association (ACC/AHA) recommended lowering the defining blood pressure for hypertension to 130/80 mm Hg.2,3 According to the new ACC/AHA guidelines, stage I hypertension is diagnosed by a systolic blood pressure of 130 to 139 mm Hg or diastolic blood pressure of 80 to 89 mm Hg. A blood pressure of ≥ 140 mm Hg systolic or 90 mm Hg diastolic defines stage II hypertension. Blood pressure should be taken by trained personnel who ensure that the patient has been at rest and seated in a chair with feet on the floor and has an empty bladder. A properly sized cuff encircles 75% to 100% of the patient’s arm. The diagnosis can be made by averaging at least two readings on at least two separate occasions using readings from ambulatory blood pressure monitoring, home self-monitoring, and/or a follow-up visit.3 The American College of Obstetricians and Gynecologists (ACOG) acknowledges the new, lower diagnostic threshold for hypertension in its bulletin on chronic hypertension in pregnancy and recommends that patients diagnosed with hypertension using these values be managed in pregnancy using the guidelines for chronic hypertension. However, because ACOG adheres to the JNC cutoff in its definition of gestational hypertension, and given that the data currently available utilize the 140/90 threshold, we will also utilize the 140/90 cutoff in this article.4
Among women, prevalence of hypertension rises from 10% in the 20- to 44-year-old age range to 78% by age 75.3 Significant disparities exist in medical treatment of hypertension. Approximately half of all adults (53.5%) and 52.1% of women have uncontrolled hypertension.5 Hypertension is more common among black adults (38.6% prevalence) and is less likely to be treated in this population. Women aged 18 to 39 are less likely than older women to have controlled hypertension, potentially predisposing women in this age group to pregnancy complications related to their hypertension. In addition, people who are Mexican-American, lack a usual medical care site, receive medical care less than twice per year, or lack health insurance are less likely to receive medical treatment for hypertension than other people with hypertension.1 Moreover, groups already at disproportionate risk of adverse pregnancy outcomes, such as black women and women lacking health insurance, are more likely to experience complications of hypertension. Given that many reproductive-aged women choose to receive their primary healthcare through their ob/gyn, there is an opportunity to diagnose, counsel on, and treat hypertension during the health maintenance exam. We have opportunities to engage in innovative patient-centered management of hypertension before, during, and after pregnancy to reduce disparities.6
Hypertension medication and pregnancy
Lifestyle modifications such as weight loss (for overweight or obese patients), a heart-healthy diet, sodium reduction, increased physical activity, and limitation of alcohol consumption3 are recommended for first-line management of hypertension. The first-line pharmacologic classes of antihypertensives are thiazide diuretics, angiotensin-converting enzyme (ACE) inhibitors, angiotensin receptor blockers, and calcium channel blockers.3 However, among women seeking pregnancy or who are currently pregnant, the preferred antihypertensive medications are methyldopa, nifedipine, and/or labetalol per the ACC/AHA.3 In clinical practice, methyldopa is less frequently used; per ACOG, it is less effective in the control of chronic hypertension and more likely to have side effects (drowsiness, headache, orthostatic hypotension).4 Women with hypertension should not be treated with ACE inhibitors, angiotensin receptor blockers, or direct renin inhibitors in pregnancy because of the risk of fetal renal damage.3 Exposure to these medications in the second and third trimesters is most concerning because of the risk of impaired fetal kidney function leading to oligohydramnios, which may in turn impair lung development. Data are less clear regarding exposure risk in the first trimester; however, most studies show a slight increased risk in congenital malformations with medications affecting the renin-angiotenin-aldosterone system.7
Hypertension is a risk factor for CVD, which itself is the top cause of death in the United States.8 Cardiovascular disorders are a top cause of maternal mortality in the United States and hypertensive disorders of pregnancy are specifically responsible for 9.4% of maternal deaths. Patients with a history of preeclampsia have quadruple the risk of developing chronic hypertension.8
Impact on pregnancy
Although most people with hypertension have no associated complications in pregnancy, hypertension is associated with increased risk for adverse health events as a result of pregnancy. In particular, chronic hypertension is associated with increased risk of gestational diabetes, postpartum hemorrhage, planned cesarean section, and preeclampsia.4 Given the increased risk of preeclampsia, women with chronic hypertension should initiate low-dose aspirin daily prior to 16 weeks’ gestation for preeclampsia prophylaxis per ACOG and the US Preventive Services Task Force.4,9 Chronic hypertension also carries fetal risks; growth restriction, stillbirth, and preterm birth are more common in pregnancies exposed to chronic hypertension.4 Both treated and untreated hypertension are associated with an increase in fetal congenital heart defects (RR 2, 95% CI [1.5-2.7] and RR 1.4, [1.2-1.7] respectively).10
Contraception and hypertension
In the following segments, we discuss the safety of various forms of contraception for people with different types of hypertension. Contraceptive counseling should be patient-centered, taking into account a woman‘s reproductive health goals and desires. Providers should consider a patient’s blood pressure control and overall cardiovascular health when discussing the risks and benefits of contraceptive methods as compared to the risks of an unintended pregnancy. Please note that the safety profiles mentioned here assume that the patient has no other comorbidities affecting the safety and suitability of these methods. We recommend a useful tool, the US Centers for Disease Control and Prevention’s Medical Eligibility Criteria (US MEC), which provides guidelines surrounding the safety of contraceptive methods for a range of given medical conditions. We have used these recommendations to inform our discussion of contraceptive methods for women with hypertension. It is important to note that the US MEC states that patients with hypertension and systolic pressures ≥ 160 mm Hg or diastolic pressure ≥ 100 mm Hg are at increased risk of adverse health events with pregnancy. As such, providers should take contraceptive efficacy into account when counseling patients. US MEC categories 1 and 2 indicate that a contraceptive method is safe and without restrictions for the specific medical condition and the advantages of the method generally outweigh any theoretical risks, respectively. Meanwhile, contraceptive methods in categories 3 and 4 should be avoided. Category 3 suggests that the theoretical or proven risks of the contraceptive method outweigh the benefits. Category 4 means that there is an unacceptable risk to the patient with use of the contraceptive method.11 US MEC recommendations for hypertensive disease and contraceptive are presented in Table 1.
Estrogen and hypertension
Estrogen therapy should be avoided in those with hypertension because it increases blood pressure while also increasing the risks of myocardial infarction and ischemic stroke.12 These relationships are thought to be dose-dependent, with higher doses of ethinyl estradiol posing a greater risk of CVD when compared to lower doses. Estrogen is theorized to activate the renin-angiotensin system and can increase systolic blood pressure by an average of 8 mm Hg.13
The US MEC states that combined hormonal contraception (CHC) poses an increased risk (category 3) for those with hypertensive disorders.14 For those with systolic blood pressure ≥ 160 mm Hg or diastolic ≥ 100 mm Hg, the risks outweigh the advantages. Additionally, the US MEC states there are unacceptable risks in using CHC in those with blood pressures above 160/100 (category 4). It is important to note that even those with blood pressure that is well-controlled with antihypertensives are still at increased risk for CVD with estrogen use.11
Progestin methods are generally considered safe in patients with hypertension. For patients with adequately controlled hypertension, progestin-only pills (POPs), etonogestrel implants, and hormonal intrauterine devices are US MEC category 1. Injectable progestin contraception, depo medroxyprogesterone acetate (DMPA) is category 2, meaning that its advantages generally outweigh theoretical or proven risks. These categories hold for patients without a formal diagnosis of hypertension who have elevated blood pressure measurements < 160 mm Hg systolic or < 100 mm Hg diastolic. However, the risk/benefit balance tips when we consider use of DMPA for patients with a systolic blood pressure ≥ 160 mm Hg or diastolic blood pressure ≥ 100 mmHg with patients who have vascular complications from hypertension. For these patients, DMPA is US MEC category 3 and all other forms of progestin are category 2. In addition, some data show that DMPA increases lipid levels with long-term use; therefore, patients with multiple risk factors for CVD-including hypertension, hyperlipidemia, diabetes, smoking, and obesity-should avoid using injectables.15
Nonhormonal methods such as behavioral methods, condoms, withdrawal, the copper intrauterine device (IUD) and permanent contraception via (partial) salpingectomy or vasectomy are safe for hypertensive patients. Regardless of the type of hypertension, the copper intrauterine device (IUD) is US MEC category 1.11 Although the copper IUD and permanent contraception have failure rates less than 1%, these other nonhormonal methods have higher failure rates and patients who choose to use barrier and behavioral methods of contraception should be informed of the failure rates of these methods in typical use. The US MEC notes that long-acting reversible contraceptives like IUDs and implants may be the best choice for patients with hypertension, likely due to their high efficacy and good safety profiles. While those are important considerations, so are a patient’s values and preferences for a contraceptive method. However, it is important to keep in mind that when weighing the risks of contraception that the alternative is potential pregnancy with its own set of risks and benefits. Shared decision-making with patients using validated tools for reproductive life planning and patient-centered guidelines for communication16 (Table 2) can improve patient satisfaction with contraceptive care.
A 34-year-old G2P2 presents to the office for her well-woman exam. She reports being in general good health. However, her primary care physician has been “keeping an eye on her blood pressure,” which was 142/78 at the woman’s last check-up. The only medication she is currently taking is an oral contraceptive pill. She is happy with this method and is considering a pregnancy in the next
6 months. Her blood pressure is 164/100.
WHICH STATEMENT BELOW IS CORRECT?
A. You recommend treating her hypertension and keeping her contraceptive method.
B. You recommend switching to a POP method of contraception, given the patient’s expressed preferences for pregnancy timing and medical history.
C. You recommend switching to the progestin injectable.