Commonly used progestogen-only contraceptives do not appear to raise the
risk for myocardial infarction.
Approximately 20 million people worldwide use progestogen-only
contraceptives, according to researchers in France. However, few studies have
assessed the potential association between the treatment and risk for
“The occurrence of
MI related to progestogen-only contraceptives has rarely
been studied so far, because of the low event rate among childbearing-age
women, as well as the lack of statistical power to assess the risk,”
according to the researchers.
To address this deficit in data, the researchers conducted a
meta-analysis of epidemiological studies examining a potential relationship
between MI and progestogen-only contraceptives. Of 28 articles found, six
case-control studies met inclusion criteria.
Two studies examined fatal MI only; two analyzed nonfatal MI only; and
the remaining two provided data on all MI events. Clinical, biological and
radiological assessments were used to define MI across all studies.
Participants’ ages ranged from 15 to 44 years, and in all studies
cases were age-matched with controls. The number of cases varied considerably
across studies, from a low of 127 to a high of 592. Similarly, the number of
controls ranged from 264 to 2,711. Studies also drew from different cohorts,
the researchers said, with two studies only including hospital controls and a
third study including controls from the hospital and the general population.
Two gathered data on women from general practice.
The researchers included studies involving oral, injectable and
implantable therapy. Four studies examined participants using oral
progestogen-only contraceptives; one analyzed those using oral and injectable
contraceptives; and one studied women using implantable levonorgestrel
(Norplant, Population Council).
The pooled OR for MI in progestogen-only contraceptive users vs.
nonusers was 1.07 (95% CI, 0.62-1.83). Although data comparing routes of
administration were lacking, the researchers found that the pooled estimated OR
for MI was 1.05 for those using oral progestogen-only contraceptives (95% CI,
Several studies also examined whether
progestogen-only contraceptive use increased risk for MI
among women with certain CV risk factors. Results from two studies indicated
that progestogen-only contraceptives did not elevate risk for MI in women with
hypertension, and another two studies suggested that progestogen-only
contraceptives did not increase risk for MI among smokers. Data regarding the
treatment’s impact on triglycerides, total cholesterol and LDL levels,
however, remain controversial.
Droxyprogesterone acetate and levonorgestrel appeared to induce higher
insulin concentrations, according to the researchers, but this result may be
dependent on a person’s weight and adipose mass.
“This meta-analysis suggests that progestogen-only contraceptive
use might be safe with respect to MI risk,” the researchers concluded.
“However, further investigation regarding this topic is needed, especially
among women with CV risk factors, and progestogen-only contraceptives must
still be cautiously used for these women.”
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Disclosure: The researchers report no relevant financial