***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Objective : To investigate the association between migraine and ischaemic or haemorrhagic stroke in young women . Design : Hospital based case-control study . Setting : Five European centres participating in the World Health Organisation Collaborative Study of Cardiovascular Disease and Steroid Hormone Contraception . Subjects : 291 women aged 20 - 44 years with ischaemic , haemorrhagic , or unclassified arterial stroke compared with 736 age and hospital matched controls . Intervention : Question naire . Main outcome measure : Self reported history of headaches . Results : Adjusted odds ratios associated with a personal history of migraine were 1.78 ( 95 % confidence intervals , 1.14 to 2.77 ) , 3.54 ( 1.30 to 9.61 ) , and 1.10 ( 0.63 to 1.94 ) for all stroke , ischaemic stroke , and haemorrhagic stroke respectively . Odds ratios for ischaemic stroke were similar for classical migraine ( with aura ) ( 3.81 , 1.26 to 11.5 ) and simple migraine ( without aura ) ( 2.97 , 0.66 to 13.5 ) . A family history of migraine , irrespective of personal history , was also associated with increased odds ratios , not only for ischaemic stroke but also haemorrhagic stroke . In migrainous women , coexistent use of oral contraceptives or a history of high blood pressure or smoking had greater than multiplicative effects on the odds ratios for ischaemic stroke associated with migraine alone . Change in the frequency or type of migraine on using oral contraceptives did not predict subsequent stroke . Between 20 % and 40 % of strokes in women with migraine seemed to develop directly from a migraine attack . Conclusions : Migraine in women of childbearing age significantly increases the risk of ischaemic but not haemorrhagic stroke . The coexistence of oral contraceptive use , high blood pressure , or smoking seems to exert a greater than multiplicative effect on the risk of ischaemic stroke associated with migraine Background and Purpose — Estimates of the incidence of ischemic stroke in young women vary widely from 0.9 to 8.9 per 100 000 per year . This study was conducted to determine the incidence and risk factors for ischemic stroke in young women in the UK . Methods — Women aged 15 to 49 with a first diagnosis and supporting evidence of ischemic stroke between January 1 , 1992 , and December 31 , 1998 , were identified from the UK General Practice Research Data base .  Age-specific incidence rates were calculated and a nested case-control study was conducted with up to 6 controls r and omly selected and matched to each case by year of birth and general practice . Crude and adjusted odds ratios ( ORs ) were calculated using conditional logistic regression . Results — The incidence of ischemic stroke was 3.56/100 000 per year . Factors associated with an increased risk were heart disease ( OR , 10.5 ) , heavy alcohol consumption ( OR , 8.5 ) , previous venous thromboembolism ( OR , 6.2 ) , treated diabetes mellitus ( OR , 4.7 ) , hypertension ( OR , 4.6 ) , migraine ( OR , 2.3 ) , and use of combined oral contraceptives ( OR , 2.3 ) . Light alcohol consumption was found to be protective ( OR , 0.17 ) . Conclusions — The crude incidence rate was lower than previously reported for the USA and Europe but higher than that reported for the UK Oxford Region . This could be because of an under-representation of mild cases or because of a true lower incidence in the UK compared with the USA and the rest of Europe . The results of the case-control study are consistent with previous studies of ischemic stroke in young women BACKGROUND A history of migraine has been proposed as a risk factor for  cerebral ischaemia in women under 45 . METHODS To investigate the association between history of migraine and cerebral ischaemia , we performed a case-control study of 308 patients aged 15 - 44 , with either transient ischaemic attack ( TIA ) or stroke , and of 591 age- and sex-matched controls prospect ively recruited in seven university hospitals . Crude and adjusted odds ratios were calculated using logistic regression analysis . FINDINGS A history of migraine was more frequent in patients than in controls ( 14.9 % vs 9.1 % ; adjusted odds ratio 1.9 , 95 % confidence interval 1.1 - 3.1 ) . In the prospect ively design ed subgroup analyses , a history of migraine reached the highest odds ratio ( 3.7 , 95 % CI 1.5 - 9 ) and was the only significant risk factor in women below age 35 ( p=0.003 ) ; atherogenic risk factors were more relevant in men and in patients older than 35 ; previous migraine attacks with aura were more frequent in stroke patients ( odds ratio 8.6 , 95 % CI 1 - 75 ) . INTERPRETATION Our findings indicated that the rare association between migraine and cerebral ischaemia is limited to women below age 35 , and suggest a need for careful clinical evaluation of comorbidity in the presence of migraine with aura The object of this study was to assess the influence of oral contraceptives ( OCs ) on the risk of cerebral thromboembolic attacks ( CTA ) including thrombotic stroke and transitory cerebral ischemic attacks . A 5-year case-control study including all Danish hospitals was conducted . All women 15 - 44 years old suffering a first ever CTA during the period January 1 , 1994 to December 31 , 1998 , were included . Controls were selected annually , 600 per year in 1994 - 1995 , 1200 per year 1996 - 1998 . Response rates for cases and controls were 88 % and 90 % , respectively . After exclusion of nonvalid diagnoses , pregnant women , and women with previous thrombotic diseases , 626 cases and 4054 controls were available for analysis . A multivariate matched analysis was performed . Controls were matched to cases within 1-year age b and s. Adjustments were made for the following potential confounders : year , length of OC use , smoking , hypertension , migraine , family CTA , and years of schooling . There were 212 and 1208 current users of OCs among cases and controls , respectively . The risk of CTA among current users of OCs decreased significantly with decreasing estrogen dose ( nonusers reference ) : OCs with 50 microg , 30 - 40 microg , 20 microg ethinyl estradiol ( EE ) and progestin-only pills implied adjusted odds ratios ( ORs ) ( 95 % CI ) of 4.5 ( 2.6 - 7.7 ) , 1.6 ( 1.3 - 2.0 ) , 1.7 ( 1.0 - 3.1 ) , and 1.0 ( 0.3 - 3.0 ) , respectively . Current users of OCs with second- ( levonorgestrel or norgestimate ) and third- ( desogestrel or gestodene ) generation progestins combined with 20 - 30 microg EE had ORs of CTA of 2.2 ( 1.6 - 3.0 ) and 1.4 ( 1.0 - 1.9 ) , respectively . After correction for differences in estrogen dose , the third- to second-generation risk ratio was 0.6 ( 0.4 - 0.9 ; p = 0.01 ) . In conclusion , high dose OCs and OCs with second-generation progestins were associated with the risk of CTA . The risk increased 2.5 times with estrogen dose increasing from 20 to 50 microg EE , and users of low-dose OCs with second-generation progestins had a 61 % higher risk-association of CTA than users of OCs with third-generation progestins Objective To assess the risk of developing cerebral thromboembolism among pregnant women and among fertile women with hypertension , migraine , diabetes , and previous thrombotic disease , and to investigate the interaction of these risk factors with the use of oral contraceptives Abstract Objective : To determine whether migraine is a risk factor for  ischaemic stroke in young women . Design : A case-control study . Setting : Five hospitals in Paris and suburbs . Subjects : 72 women aged under 45 with ischaemic stroke and 173 controls r and omly selected from women hospitalised in the same centres . Main outcome measures : Ischaemic stroke confirmed by cerebral computerised tomography or magnetic resonance imaging ; history of headache recorded with structured interview  , and diagnosis of migraine assessed by reproducibility study . Results : Ischaemic stroke was strongly associated with migraine , both migraine without aura ( odds ratio 3.0 ( 95 % confidence interval 1.5 to 5.8 ) ) and migraine with aura ( odds ratio 6.2 ( 2.1 to 18.0 ) ) . The risk of ischaemic stroke was substantially increased for migrainous women who were using oral contraceptives ( odds ratio 13.9 ) or who were heavy smokers ( > /=20 cigarettes/day ) ( odds ratio 10.2 ) . Conclusions : These results indicate an independent association between migraine and the risk of ischaemic stroke  in young women . Although the absolute risk of ischaemic stroke in young women with migraine is low , the reduction of known risk factors for stroke , in particular smoking and use of oral contraceptives , should be considered in this group 
    Output:
    
No evidence was found on other hormonal contraceptives or on risk of myocardial infa rct ion .