Combined Hormonal Contraception and Venous Thromboembolism
January 2007
in “
The European Journal of Contraception & Reproductive Health Care
”
TLDR Birth control pills increase the risk of blood clots, especially within the first year and with certain types.
The 2007 document reviews the risk of venous thromboembolism (VTE) associated with combined hormonal contraceptives (CHCs), particularly combined oral contraceptives (COCs). It finds that COCs increase the risk of VTE, especially in the first year of use, with those containing desogestrel or gestodene posing a two-fold greater risk and those with cyproterone acetate a four-fold greater risk compared to levonorgestrel or norethisterone. There is no significant data for COCs with other progestins like norgestimate, chlormadinone acetate, or drospirenone. The contraceptive patch has a similar risk to COCs, while data on the vaginal ring is insufficient. Routine screening for thrombogenic mutations is not recommended due to the low cost-effectiveness, and no laboratory tests can predict VTE risk in asymptomatic women. The document stresses the importance of evaluating personal and family medical history, blood pressure, and BMI before prescribing COCs and keeping up-to-date with new data on contraceptive products. The document does not specify the number of people involved in the studies it references.
