Abstract
Combined oral contraceptives (COCs) have been available for decades. While there is a wide knowledge of certain risk factors or precautions to be taken during their use, thanks to scientific progress, new insights continue to emerge that significantly influence the use of COCs. In this publication, we provide a summary of the most important and most recent key points that need to be considered when counselling women regarding COC use. One of the primary side effects of CHC use is the increased risk of venous thromboembolism, which is greatly influenced by personal and family medical history. However, the composition of COCs also plays a crucial role, with the lowest increased risk expected in combinations of ethinylestradiol and second-generation progestins, such as levonorgestrel, as well as a combination of estradiol and nomegestrol. Estetrol has recently become available as a new estrogen component in COCs, showing fewer effects on endocrine and metabolic parameters. Whether this transfers to a lower increase in the for thromboembolism remains to be seen. Caution should be taken when counselling specific patient populations. For instance, patients with BRCA1/BRCA2 mutations experience a significant further increase in their high risk for breast cancer when using COCs, and this risk increases further with duration of use. When counselling patients with migraines, it is essential to consider the significant increase in the risk for strokes associated with COC use, particularly in patients experiencing migraine with aura. Progestin-only pills containing desogestrel have shown to reduce the frequency of migraine attacks and do not elevate the risk of stroke. For patients seeking advice after using emergency contraception, timing of the initiation of COC intake should be taken into account. Due to the risk of interactions between both methods the administration of COC should start no earlier than 5 days after ulipristal acetate intake.