I'm 7 months pregnant and have chronic urticaria and angieodema. i used to take at lease 500mg of benadryl (diphenhydramine). what is the max limit for a pregnant woman?

50 mg?: Did you mean 50 mg of benadryl (diphenhydramine)? I have never heard of 500 mg ever being used to treat any condition. 50 mg of Benadryl (diphenhydramine) is considered the usual adult maximum dose and many pregnant women have used this dosing. Benadryl (diphenhydramine) is a category b pregnancy drug which means it has a low likelihood of harming the fetus, but randomized controlled studies have not been performed.