According to a meta-analysis published in theThrombosis Research,combined oral contraceptives (COCs) may significantly increase the risk for venous thromboembolism (VTE) compared to levonorgestrel with 30-40 µg ethinylestradiol. The meta-analysis also reports that the association varies depending on the progestogen type and dose of ethinylestradiol.
Researchers conducted a meta-analysis of 17 studies (case-control, 11; cohort studies, 6) identified through a literature search on the PubMed, EMBASE, and LIVIVO databases.
The pooled results of all trials showed that overall risk for VTE was higher with all COCs. The pooled results of 14 trials showed a higher risk for VTE with desogestrel+estrogen 30-40 μg compared with the LNG/EE 30-40 µg (relative risk [RR], 1.46; 95% CI, 1.33-1.59). Compared with LNG/EE 30-40 µg, women receiving gestodene+ethinylestradiol (GSD/EE) 30-40 µg and GSD/EE 20 µg were at 1.27-fold risk (95% CI, 1.15-1.41) and 1.18-fold (95% CI, 0.93-1.64) risk for VTE, respectively. Compared with LNG/EE 30-40 μg, risk for VTE was higher with drospirenone+ethinylestradiol 30-40 µg (RR, 1.40; 95% CI, 1.26-1.56 or OR, 1.54; 95% CI, 1.34-1.77) and was slightly higher with cyproterone+ethinylestradiol 30-40 μg (RR, 1.29; 95% CI, 1.12-1.49 or OR, 1.43; 95% CI, 1.15-1.79).
“It is essential for consider a COC with the lowest possible dose of ethinylestradiol to minimise the VTE risk in young healthy women.”, the authors commented.