The risk of cerebral vein thrombosis associated with different types of combined hormonal contraceptives: a case-control study.

BACKGROUND

Cerebral vein thrombosis (CVT) is a rare manifestation of venous thrombosis predominantly affecting women due to female-specific risk factors, such as combined hormonal contraceptive (CHC) use. However, limited data exist on how different CHC types affect CVT risk.

OBJECTIVES

This study aimed to evaluate CVT risk across CHC types and to investigate their combined effects with thrombophilia, family history of thrombosis, and body mass index.

METHODS

This case-control study included women with CVT (cases) and healthy women (controls) of childbearing age who were referred to our Center from 1992 to 2019 for a thrombophilia work-up. Women with pregnancy- and cancer-related CVT were excluded.

RESULTS

In total, 206 cases (157 CHC users, 49 nonusers) and 868 controls (196 CHC users, 672 nonusers) were included. CHC users had a 10-fold higher risk of CVT (odds ratio [OR]: 10.9; 95% CI: 7.7-15.7) than nonusers. Higher estrogen doses increased the risk in a dose-response manner. Variable estrogen dose CHC carried a 6-fold increased risk, similar to progestin-only pills. The risk increased with fourth-generation pills (OR: 28.3; 95% CI: 14.6-54.9). Thrombophilia abnormalities had a synergistic effect with CHC use (OR: 67.8; 95% CI: 34.6-133.0). For CHC users with a positive family history of thrombosis, the OR of the combined effect varied from 47.0 (95% CI: 24.4-90.7) to 254.1 (95% CI: 79.8-809.0), depending on the absence or presence of thrombophilia abnormalities.

CONCLUSION

This study underscores the complex interaction between CHC type and other thrombotic risk factors in influencing CVT risk among women of childbearing age.