Well this topic has been on my mind a lot latey, seeing as I leave for WDW in 2 days and I am 8 weeks pregnant. Each stage of the pregnancy is a different trip. My 1st trip I took pregnant I was 32 weeks (just starting the 8th month) At that time there was nothing out there for pregnant women. I just got home from my Ob-gyn and while looking through the magizines his office gave out free there was an article on being pregnant at WDW. So far nothing I hadent heard before, it was in epregnancy and was written by Kathleen M Reily. You might be able to find it on line. (the magizine had Marlee Matlin on the cover.)
The unoffical guide also has a page on going to WDW pregnant.
5 months is a great time to go, morning sickness should be over, but not as big as she is going to get. What time of year will you be there. Be careful if it is too hot. My Doc warned me to be very careful with the sun and drink lots of water.
At this point it is so early I can ride any ride I feel up too. My concern is not feeling well and no engrery. Oh well can't have it all. My Doc did take pitty on me and give me some free samples of a special med they give to cancer patients to ease nausea. It works very well, but I am saving it for when I really need it. We plan to take lots of breaks and just have a relaxing trip. We also will be staying at VL (Villas) it will be our 1st trip there so I will have to let you know how great it is when we get back.
Tell your wife not to worry, she will not be the only pregnant women there. Congradulations and good luck. Wear comfortable shoes, remember if you really need it you can even rent a whell chair. There is lots of nice places to take a break. If it is just the too of you be sure to spend lots of time at Epcot, and then some time at MK dreaming about how much your child is going to love that place. (my DD who we went to WDW pregnant is a true WDW fan, this will be her 4th trip, and she isn't 3 yet.)