Study Reveals Increased Stroke Risk Linked to Birth Control in Young Women

Recent research presented at the European Stroke Organization Conference (ESOC) 2025 suggests that the use of combined oral contraceptives (COCs) significantly elevates the risk of cryptogenic ischemic stroke (CIS) among young women. The findings highlight a concerning association that calls for increased awareness regarding hormonal contraceptive use in this demographic.

Cryptogenic ischemic stroke, characterized as a stroke with no identifiable cause, accounts for nearly 40% of ischemic strokes in young adults. Despite its prevalence, the role of gender-specific risk factors, including contraceptive use, has not been sufficiently examined in prior studies. While earlier research has established a link between combined oral contraceptives and stroke risk, this study uniquely focuses on young women experiencing cryptogenic strokes.

The study, titled 'Searching for Explanations for Cryptogenic Stroke in the Young' (SECRETO), involved 268 women aged 18 to 49 diagnosed with CIS and an equal number of age-matched control participants without stroke histories across 14 European centers. Among the participants, 66 stroke patients and 38 controls reported using combined oral contraceptives. After adjusting for age and known comorbidities such as hypertension, smoking, migraines with aura, and abdominal obesity, the use of COCs was associated with a tripling of stroke risk, with an odds ratio of 3.00.

No significant interactions were found between COC usage and these known risk factors, suggesting that the increased risk remains even when accounting for other health issues. The lead researcher emphasized that the results corroborate previous findings linking hormonal contraceptives to higher stroke risk, and the association persists despite controlling for established risk factors, indicating potential involvement of additional genetic or biological mechanisms.

Most participants in the study utilized formulations containing ethinylestradiol, averaging a dosage of 20 micrograms, while other estrogen types were also assessed. To ensure consistency, the researchers calculated the equivalent estrogen dosage for each participant.

While the study provides critical insights, the researchers advocate for larger scale studies to explore whether different formulations of hormonal contraceptives carry varying levels of risk. Such knowledge could aid in guiding women toward safer contraceptive choices.

The researchers also advise healthcare professionals to exercise caution when prescribing combined oral contraceptives to women with existing vascular risk factors or a history of ischemic strokes. The findings underscore the necessity for thorough evaluations of stroke risk in young women, particularly those with additional health concerns.

Future research will focus on the biological and genetic mechanisms that may explain the observed relationship between COC use and elevated stroke risk, aiming to enhance understanding of how hormonal contraceptives may independently contribute to stroke incidence.