**Core Concept**
The Mirena is a type of hormonal intrauterine device (IUD) that releases levonorgestrel, a progestin, to prevent pregnancy. The device is designed for long-term use, but its effectiveness and safety may decrease over time.

**Why the Correct Answer is Right**
Mirena IUDs are designed to be effective for up to 5 years. After this period, the device's effectiveness may decrease due to the gradual release of levonorgestrel, which can lead to reduced contraceptive efficacy. The American College of Obstetricians and Gynecologists (ACOG) recommends replacing the Mirena IUD every 5 years to maintain optimal contraceptive performance.

**Why Each Wrong Option is Incorrect**
**Option A:** Removing the Mirena IUD after 2 years is not recommended because it may not provide the full 5 years of effective contraception, increasing the risk of unintended pregnancy.

**Option B:** There is no standard recommendation for replacing the Mirena IUD every 3 years. This option may not provide the optimal duration of effective contraception.

**Option C:** Some IUDs, such as the copper T380A, may be effective for longer than 5 years, but the Mirena IUD's efficacy decreases after this period.

**Clinical Pearl / High-Yield Fact**
It's essential to counsel patients on the need for regular follow-up and replacement of the Mirena IUD every 5 years to maintain optimal contraceptive performance and prevent unintended pregnancy.

**Correct Answer:** C. 5 years.