**Question:** One of the health benefits of the use of combined oral contraceptives in pre-menopausal women is that these contraceptives reduce the risk of:

A. Ovarian cancer
B. Endometrial cancer
C. Stroke
D. Deep vein thrombosis

**Correct Answer:**

**Core Concept:** Combined oral contraceptives (COCs) are a type of hormonal contraceptive that contain both estrogen and progestin hormones. They primarily work by suppressing ovulation and thickening the cervical mucus to prevent sperm from reaching the uterus. In pre-menopausal women, COCs have a range of additional health benefits.

**Why the Correct Answer is Right:**

Combined oral contraceptives reduce the risk of endometrial cancer in pre-menopausal women. The mechanism is related to the hormonal components of COCs, specifically the progestin component. Progestins inhibit the growth of endometrial cells, reducing the risk of endometrial cancer development.

**Why Each Wrong Option is Incorrect:**

A. Ovarian cancer reduction is not a direct benefit of COCs. While the hormonal components may have indirect effects on ovarian health, the primary focus of COCs is preventing pregnancy, not ovarian cancer prevention.

B. COCs do not directly reduce the risk of endometrial cancer but may indirectly help by reducing the risk of obesity and type 2 diabetes, both of which are risk factors for endometrial cancer.

C. Deep vein thrombosis (DVT) is a potential side effect of COCs, not a benefit. The risk factors for DVT include obesity, smoking, and physical inactivity. COCs may increase the risk of DVT, especially in women with these co-morbidities.

D. Stroke risk reduction is not a direct benefit of COCs. While some studies indicate a potential decrease in stroke risk due to reduced blood pressure and lipid profiles, the primary focus of COCs is preventing pregnancy, not stroke prevention.

**Clinical Pearl:** In clinical practice, consider recommending COCs for their potential health benefits when discussing contraception options with pre-menopausal women. However, be aware of the potential side effects and contraindications, such as a history of venous thromboembolism or severe hypertension, and consult with the patient to weigh the risks and benefits.