My IUD has been in for 10 years, and I am supposed to have it removed after 10 years. What could happen if I just go ahead and leave it in for a couple more years, since I am 42 now and expect to go through menopause in a few years? Does it lose its effectiveness? It is a Paraguard T-380A.

Gloria

The Paraguard IUD has copper wrapped around it, which acts like a spermicide, killing the sperm before they can reach the egg. This copper slowly dissolves over time. Currently the Paraguard IUD is FDA-approved for 10 years of use; it may be effective longer than that, but we really don't know for how much longer.
At age 42, you have another nine years on average before you will go through menopause and be sterile -- this is almost double the approved life of your IUD. If you do not wish to have an unplanned pregnancy, I would strongly encourage you to have your current IUD replaced, or have it removed and use some other type of contraception.