Risk of Stroke in Women Using Levonorgestrel-Releasing Intrauterine Device for Contraception

Area of Science:

• Reproductive Health
• Neurology
• Cardiovascular Medicine

Background:

• Combined hormonal contraceptives containing progestins and ethinylestradiol are linked to increased ischemic stroke (IS) risk.
• Progestin-only contraceptives, such as levonorgestrel-releasing intrauterine devices (LG-IUDs), have not been associated with increased IS risk, with some studies suggesting a reduced risk.
• The impact of LG-IUDs on intracerebral hemorrhage (ICH) risk has not been previously investigated.

Purpose of the Study:

• To investigate the risk of ischemic stroke (IS) and intracerebral hemorrhage (ICH) in women using LG-IUDs compared to non-users of hormonal contraceptives.

Main Methods:

• A Danish historical cohort study (2004-2021) included nonpregnant women aged 18-49.
• Data on incident IS and ICH were collected from nationwide Danish registries.
• Poisson regression models adjusted for relevant covariates were used to analyze the association between LG-IUD use and stroke risk.

Main Results:

• The study analyzed over 11.9 million person-years from 1.68 million women.
• LG-IUD users exhibited a 22% lower incidence rate of IS compared to non-users (Incidence Rate Ratio: 0.78).
• No significant increase in ICH incidence was observed among LG-IUD users (Incidence Rate Ratio: 0.94).

Conclusions:

• LG-IUD use is associated with a reduced incidence of ischemic stroke.
• LG-IUDs do not elevate the risk of intracerebral hemorrhage.
• Levonorgestrel's potential cardioprotective effects warrant further investigation for IS prevention.