Oral contraceptives and stroke

A review suggests that (1):

• the evidence suggests there is no increase in risk of haemorrhagic stroke associated with the use of the combined oral contraceptive (COC)
• there is however evidence of an increase in risk of ischaemic stroke in women taking either second- or third- generation COCs. This risk is greater if there associated risk factors:
  • risk of stroke in those women taking a COC who do not smoke and are not hypertensive is about 1.5 times that of non-COC users
  • there is evidence that if a COC user has hypertension then the risk of a ischaemic stroke is about 3 times that of normotensive COC users

A MeReC review (2) states:

• COCs are associated with a very small increase in the absolute risk of ischaemic stroke in non-smoking, normotensive women
• COCs should be used with caution in any woman with risk factors for cardiovascular disease (e.g. obesity, age over 35 years, smoking) and avoided in women with severe or multiple risk factors
  
  

Data from a systematic review and meta-analysis of observational studies (3) revealed use of the oral contraceptive pill in people with migraine may be a significant risk factor for developing stroke:

• the risk of stroke in those taking oral contraceptives was very significant (relative risk 8.72, 5.05 to 15.05). Note that the authors state that the risk of stroke among oral contraceptive users was very high but qualified this in stating that these data came from only three studies

Reference:

1. Drug and Therapeutics Bulletin 2000; 38 (1): 1-5.
2. MeReC Bulletin 2006;17(2):1-9.
3. Etiminan M et al. Risk of ischaemic stroke in people with migraine: systematic review and meta-analysis of observational studies. BMJ 2005; 330:63.