Hormonal contraception use and insomnia: A nested case-control study

Evidence is limited concerning possible associations between the use of hormonal contraception and insomnia. We applied the nested case-control design on a nationwide sample of women, aged 15-49 years, derived from national health care registries to characterize the association between the use of hormonal contraception and the occurrence of insomnia. There were altogether 294,356 users and 294,356 non-users of hormonal contraception. 11,105 new cases of insomnia emerged among the 1,148,969 person-years of the follow-up period of two years. All the significant associations of hormonal contraception with insomnia emerged among the participants aged 34 years or younger, and if only the tertiary care data was concerned, among the those aged 15-19 years. The users of the fixed combination of drospirenone and ethinylestradiol as well as that of cyproterone and ethinylestradiol had significantly decreased odds for insomnia, whereas the users levonorgestrel-releasing intrauterine devise as well as those of vaginal ring with etonogestrel and ethinylestradiol had significantly increased odds for insomnia as compared with non-users. Our findings suggest that different products prescribed for hormonal contraception may be differentially associated with the occurrence of insomnia.