S. -
I too went through this after I had my first baby 2 1/2 years ago. I agree exactly with what Stacey M has said...believe it or not, it will pass. I ended up having to go to the sleep center at U of M because nothing seemed to work. I thought my sleeping issues would never resolve itself but they did. I went back to my OB to talk to him about this and he says he sees this from time to time. When I saw him, he was able to rule out postpartum depression (which I did not think I had either) and also checked my thyroid. He told me not to take sleeping pills and if it did not resolve in a few weeks, he would send me on to U of M. Well, it did not so I went to U of M. Basically, the sleep experts there will tell you that your body clock ends up getting completely off and your body just stops knowing what to do...apparently, this happens to a lot of people who do shift work (i.e. working midnights). They put me on a strict sleep schedule (basically, no napping, alcohol, caffeine and going to bed at the same time every night and not too early or late either) for about 3-4 weeks and it corrected itself. They had me keep a record of certain things like when I went to bed, how long I slept, how many times I woke up, etc. This completely corrected my problem and I never took one sleeping pill! Things have been fine since as well, however, baby #2 is due in June and I fully expect this to happen again (hope not!). Also, I could only go through this treatment once my baby was sleeping through the night or it would have been ineffective. I never told many people about all of this while I was going through it but since then, I have heard of so many people who have had this. One more thing, the dr's at UofM told me some people are just more prone to this than others....lucky us! One last thing, you mentioned you were 4 months postpartum and this is when it was at its worst for me...I went to U of M at about 7 months postpartum. You might want to have your doctor check your thyroid to rule this out...apparently, thyroid levels can bounce all over the place postpartum and cause this.