The changing scene--an unnecessary pill crisis

Area of Science:

• Reproductive Health
• Pharmacovigilance
• Cardiovascular Epidemiology

Background:

• Early studies suggested increased venous thromboembolism (VTE) risk with third-generation oral contraceptives (OC).
• Methodological limitations and biases in initial studies were suspected to inflate risk estimates for third-generation OC.

Purpose of the Study:

• To re-evaluate the association between third-generation and second-generation oral contraceptives (OC) and the risk of venous thromboembolism (VTE).
• To assess the risk of arterial thromboembolism (myocardial infarction, ischemic stroke) associated with different generations of oral contraceptives.

Main Methods:

• Six new studies and analyses were conducted, including population-based database analyses from the UK and Germany, and a Danish population-based study.
• Methodological improvements addressed biases identified in earlier case-control studies.
• Re-analysis of existing data using updated techniques was also performed.

Main Results:

• The new studies did not confirm a higher VTE risk for users of third-generation OC compared to second-generation OC.
• Data on arterial thromboembolism showed no significant difference between OC generations.
• One study indicated a statistically significant reduction in acute myocardial infarction risk from first- to third-generation OC.

Conclusions:

• There is likely no increased risk of arterial thromboembolism with low-dose estrogen OC in properly screened young women.
• Findings suggest that earlier concerns about increased VTE risk with third-generation OC may be unfounded.
• These results necessitate a re-evaluation of previous interpretations regarding OC use and thromboembolic risk.