Are you one of the millions of women worldwide who take progestin-only contraceptives? Most women take combined contraceptives, a blend of progestin and estrogen, although their safety is still debated. But recent studies found that women on the Pill had twice the risk of heart attacks compared to those not taking contraceptives.

Women at increased risk of heart disease – including smokers and those with high blood pressure - may be counseled to take the progestin-only pills (POC), as past research had found no link between POCs and heart attack. But is that recommendation safe?

Heart attacks are uncommon among childbearing-aged women. The annual incidence is two per million among healthy women aged 30-34 years, and increases to 20 per million between 40-44 years. Many studies have debated the relationship between combined oral contraceptives (COC) and cardiovascular disease risk. While some of them failed to show an association between COC use and heart attack risk, others found an increased incidence of coronary events among COC users.

A recent Journal of Clinical Endocrinology and Metabolism study examined several previous publications to determine the cardiac risks of progestin–only contraceptives. The studies reviewed included more than 1,800 women between 16-44 years of age on birth control and compared those to women not taking the hormones.

The contraceptives studied included so-called mini-pills such as Micronor and Ovrette, plus other progestin-only products such as implants or shots, including depot medroxyprogesterone acetate (DPMA). The study found no link between POCs and heart attacks, and therefore supports the recommendation of POCs in women at increased cardiac risk.

In general, the American College of Obstetrics and Gynecology (ACOG) recommends POCs over COCs for patients who are cigarette smokers older than 35, or have coronary artery disease, congestive heart failure, high blood pressure with vascular disease or age greater than 35,or diabetes with vascular disease or age greater than 35 – all conditions associated with increased risk of heart attack and stroke.

ACOG also recommends POCs for women with a history of migraines, thromboembolism (such as a pulmonary embolism), strokes, lupus with vascular disease, nephritis (an inflammatory condition of the kidneys), and elevated triglycerides.

The World Health Organization (WHO) recommends that women younger than 18 and older than 45 years avoid POCs due to concerns about decreased bone mass. According to WHO, women who are immediately postpartum may initiate POCs if they’re not breastfeeding, and if breastfeeding, women should wait until at least six months after giving birth.