Trends in the use of hormonal contraception in Estonia 2005-2019 and the risk of arterial and venous thromboembolism: a population-based study.

Purpose: To describe trends in hormonal contraceptive use, incidence of thromboembolism and presence of risk factors for thromboembolism among the users in Estonia.

Material And Methods: Data of 223 312 female patients aged 15-49 years in 2005-2019 from national health insurance databases was derived. Annual prevalence rates of hormonal contraceptive users, incidence rates of thromboembolism and prevalence rates of risk factors were calculated.

Results: Between 2005-2019 usage of progestogen-only contraceptives (POCs) increased steadily (from 24 to 135 users per 1000 population), whereas combined hormonal contraceptive (CHC) use declined (from 209 in 2012 to 161 users per 1000 population in 2019). During the study period, 390 cases of venous thromboembolism and 108 arterial thromboembolism coincided with hormonal contraceptive use. Incidence rate for venous thromboembolism was 5.0 (95% CI 4.5-5.5) and for arterial thromboembolism 1.4 per 10 000 person-years (95% CI 1.1-1.7) among hormonal contraceptive users. Age adjusted incidence of venous thromboembolism among CHC users was 5.8 (95% CI 4.1-8.2) times higher than in POC users. Among CHC users, 10.3% had more than one risk factor for thrombosis.

Conclusions: In regards to the risk of thromboembolism, wider use of POCs and declining prevalence of CHCs in Estonia is positive trend. Still, women with history of thrombosis receiving CHC is a serious concern.