I used to sleepwalk, until my early 20s - also had night terrors but those stopped a bit earlier. Completely genetic - my father did these too, and for longer actually.

Usually I'd head right out of the house or wherever I was when sleepwalking - I usually lived with other people, or otherwise I might not even have known I'd done it. I'd be having a dream and the dream would just keep going the whole time and what I'd be doing in my sleepwalking was just an approximation of what I was doing in the dream.

Thinking very hard about what I remember of how it felt, and particularly how it felt when someone actually woke me up in the act (sometimes they just followed me until I came back and got back in bed) -- when I would sleepwalk I was in a state a lot deeper than sleep, more like a coma or something, or--probably a better analogy--like being under anesthesia - waking up from it seemed to take a very long time and was like swimming very slowly up against a great pressure of water or something; even tho your eyes are open and you might be looking at the person following you and even talking to them, you don't see what's there, you see something else. When they touch you or do whatever they do to actually wake you, your vision gets all blurry and so does your hearing and it's very confusing as what's actually there begins to seep in over what you thought was around you.

I think that something goes on in brain chemistry that causes this particular kind of unconsciousness - it's not really sleep. I'd bet that because of your pregnancy you are having a chemical shift that's putting you into this deep level and it will probably stop once the chemicals shift again. And--speaking from experience--once you stop being able to sleep deeply thru any night (which happens once you have kids), sleepwalking stops.

I think the state of anesthesia is the best description, because now that I think of it, I've had full-body anesthesia three times in my life, and all three times--as soon as they started to actually cut me, I started climbing off the table, despite by all accounts being completely out. They had to give me more of the drugs and were always amazed--and always told me about it after. I actually remember doing this -- the "I'm outa here" decision--and during both times, despite them saying it was impossible, I didn't feel pain but I did feel them poking and manipulating and positioning my body and it was extremely annoying and I got more and more irritated and fed up, and I do recall deciding the last time that, if they poked me one more time, I was leaving!! Luckily they stopped right then. Later in recovery I'd pull all the tubes and monitors out, allegedly still unconscious, and try to climb out of the bed. Once I went right over the rails and dislocated my hip as a result, which hurt so much I actually did wake up for a moment.

A lot of animals will react this same way under anesthesia - they just want to get away from the drug and from what's going on, and that instinct is stronger than any drug.

I've never done anything weird or violent in my sleepwalking, according to reports. Just very purposely took off and headed elsewhere, sometimes stopping and staring at things for a long time.