According to wisegeek.com, "Pregnancy brain is a condition that affects expectant mothers, usually during the first and third trimesters. Sometimes known as placenta brain or baby brain drain, the condition is usually characterized by short-term memory loss or forgetfulness."
A recent Australian study also confirms it.

The above photo I found on a blog (lilsugar.com), and portrays exactly how I feel lately.
I'm just now getting into the second trimester and pregnancy brain is really hitting me. Steven needs to revoke my cooking privileges. Last weekend, I made muffins for us to eat in the car on the way to his eye doctor appointment. When we returned home, we found that I had left the oven on. Thankfully nothing was on fire.
This morning I decided to try muffins again. For some reason it took longer than usual for them to bake. When I took them out and turned the oven off, I realized I had cooked them on the preheat setting!
Gee whiz. I'm losing it.