We have many theories on why Meg hasn't been sleeping through the night lately:
Maybe she's hungry
Last night we did everything we could to make sure Meg would NOT wake up in the middle of the night because she was hungry. Before bed, we fed her a bowl of oatmeal cereal. Then I nursed her. Then we gave her a 4 ounce bottle. She slept through the night. I don't know if that's why, though. She also slept through the night Tuesday and we didn't give her oatmeal (she did nurse and get the bottle).
Daylight savings time
Its light for so long in the evenings, she seems to think when we put her to bed, we're actually putting her down for a nap. She sleeps 4 hours, then wants to get up and play.
Taking too many naps
She seems to be doing fine on days where she only takes two half-hour naps. So maybe when she takes longer naps, she's just not tired at night. She's been transitioning to one nap. Should we never let her take two?
The two nights she's gotten up were the two nights I came home from work and immediately fell asleep on the couch. Both nights she's just wanted to hang out with mommy in the middle of the night. Maybe she misses playing with me in the evenings?
Last night, we tried to fix as many of those things as we could. As I said, we fed her oatmeal so she wouldn't be hungry as soon. I played with her all evening, so she got a lot of mommy time. We emphasized the bedtime routine (more books, more rocking, to drill into her head its BEDTIME, not naptime). We couldn't do much about the naps, since she was at daycare all day.
I think tonight will be the real test, since she tends to sleep through every other night. Even when she's getting up at night because she's sick, she does it every other night. So we'll see...