Hello Meg, congratulations with your pregnancy!

I found not much on this issue regarding the WD, only http://chetday.com/meatandpg.htm

I think if you check on South Beach you can find answers:

http://forum.lowcarber.org/showthread.php?t=226258

I would advise to eat healthy to satisfaction, my wife has given birth to three children and still has a beatiful figure, thanks to moderate eating and sport. If you just adjust the WD to eating some more at daytime and some less and night you may have a good base to change back after the pregnancy.

Since a lot of women who take care do get back really nice bodies I would not worry at all!