Getting married during pregnancy
I'm tempted to create bullet points, but I'll leave those for another post. Getting married during pregnancy can be a wonderful thing, and there are stunning maternity wedding dresses on the market. There is a big practical advantage to getting married during pregnancy. You will not have to go through special procedures to get your partner listed on the baby's birth certificate, and husbands are accepted as next of kin.
That means that your husband will get to make medical decisions for you and your baby if you encounter any complications during birth (hopefully, you won't need this!). On the downside, weddings are big events and you may well be tired during pregnancy. If you are feeling rough, a big wedding may drain the energy right out of you and many couples really want to use their wedding day as an opportunity to throw a big party!
Waiting until later
Waiting until after your baby is born may give you the chance to wear the dress of your dreams, and to have pictures of your cute baby included, rather than just your baby bump. On the other hand, your honeymoon will be quite different if you are also taking a baby with you.