RT Journal Article SR Electronic T1 Do hormonal contraceptives influence asthma severity? JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 1028 OP 1033 DO 10.1183/09031936.99.14510289 VO 14 IS 5 A1 L Forbes A1 D Jarvis A1 P Burney YR 1999 UL http://erj.ersjournals.com/content/14/5/1028.abstract AB There is some evidence that endogenous progesterone and oestrogen levels influence asthma severity in females, but little is known about the effects of hormonal contraceptives. This study aimed to describe how females with asthma perceived the effects of hormonal contraceptives on symptom severity, and to describe the association between asthma severity and current use of hormonal contraceptives. A questionnaire was sent to 891 females with asthma aged 20-30 yrs recruited from general practice registers in South London, UK. It asked about perceptions of the effects of hormonal contraceptives on asthma severity, about current use of hormonal contraceptives, and included an asthma quality of life questionnaire as a measure of asthma severity. About 6% of respondents who had ever used hormonal contraceptives reported that these had influenced asthma severity, -4% reporting worsening and 2% an improvement. There were no significant differences in asthma quality of life score between females currently taking hormonal contraceptives and those not, between those taking combined and progesterone-only preparations, or between users of different progestagen types. This study found no evidence of any important effect of hormonal contraceptives or their components on asthma severity in a group of females with relatively mild asthma.