I have two littl egirls and my twitching subsided a great deal the two times I was pregnant. In fact, it is what had clued me in to consider hormones and the effect they have on this disorder. When you are pregnant there is a flood of progesterone, and estrogen too of course. However, I think that progeseterone dominates the estrogen when you are pregnant and progesterone has a calming effect on the nervous system. Estrogen has a stimulatory effect, and can be worse for certain people with disorders like seizures. My youngest just turned one and I have been on the mini pill (progesterone only) ever since I have had her and knock on wood, my symptoms have stayed pretty minimal.
In my last pregnancy my twictching was horrid for the first 7 weeks. Well I had some spotting start and my ob gyn tested my progesterone because low levels can cause a misscarraige and low and behold my levels were low. He started me on Prometrium (progesterone) and my twicthing improved immediately.
This is all speculation of course, but if feasible, it might not hurt to try a birth control option after you have your baby that has a stronger progestin in it. I think Mircette and Yasmin are two that have a pretty strong progestin in them.