Study: Contraceptive Use Significantly Increases Risk of Stroke and Myocardial Infarction

Simian Practicalist
Jun 27
2 min read

A Danish study by H. Yonis et al titled “Stroke and myocardial infarction with contemporary hormonal contraception: real-world, nationwide, prospective cohort study” published on 12 February 2025 supports what one can guess based on Natural Law and commonsense.

The text is about 9 pages, which is short and relatively easy to read. It is a nationwide prospective cohort study of all Danish women aged 15–49 years from 1996 to 2021. The weighted median age is approximately 34 years. Women with certain medical histories were obviously excluded.

A total of 2 025 691 women aged 15 to 49 years contributed with 22 209 697 person years of follow-up time.

For no contraceptive use, the ischaemic stroke rate was 18 per 100 000 person years and the myocardial infarction rate was 8 per 100 000 person years.

For combined oral contraceptives compared to no contraceptive use: the ischaemic stroke rate was 2.0 (95% CI: 1.9–2.2) times and the myocardial infarction rate was 2.0 (95% CI: 1.7–2.2) times.

For combined vaginal ring compared to no contraceptive use: the ischaemic stroke rate was 2.4 (95% CI: 1.5–3.7) times and the myocardial infarction rate was 3.8 (95% CI: 2.0–7.3) times.

For combined hormonal patch compared to no contraceptive use: the ischaemic stroke rate was 3.4 (95% CI: 1.3–9.1) times and no myocardial infarction cases were observed.

For progestin-only oral contraceptives compared to no contraceptive use: the ischaemic stroke rate was 1.6 (95% CI: 1.3–2.0) times and the myocardial infarction rate was 1.5 (95% CI: 1.1–2.1) times.

For subcutaneous progestin-only implant compared to no contraceptive use: the ischaemic stroke rate was 2.1 (95% CI: 1.2–3.8) times and the myocardial infarction rate “could not be calculated due to the very low number of events”.

There were other observations but one gets the idea. The risk of ischaemic stroke and myocardial infarction remained stable with “no consistent change in risk was observed over time”.

Even though the absolute numbers are low, the increased risks are statistically significant. Unfortunately, the paper doesn’t discuss the possible mechanisms in detail, only mentioning the study’s consistent with the previous observations.