Do pregnant rats need special care?

Lots of food: calories, protein, cheese, carrots, sweet potatoes, cat food, torn paper strips for nesting (non-scented tissue or paper towels).
Watch for vaginal bleeding. If no babies in 12 hours go to vet for Oxytocin injection to induce labor. If breeding date is known and bleeding is well before term, induce labor.
Some females will reabsorb the babies if they fail to give birth. Put them on antibiotics during this period.
Some people would advise taking the rat to the vet right away, but this is a matter of opinion on the part of some people and if you are not sure what to do, you can always call the vet and ask what the best course is. I haven't lost any rats yet and haven't taken any to the vet either for labor problems. Best to do what you feel is right.