When I was at my parents' place, my mother used to make prawns curry but made sure they were cooked very well. Freshness is key, so avoid eating them at cheap local joints.
I totally understand wanting to eat your favorite seafood! Yes dear, you can have them but please ensure they are fresh and cooked completely to keep baby safe.
Prawns are perfectly safe and a good source of protein, but strictly no raw sushi or half-cooked preparations. Make sure they are cleaned properly at home.
My doctor at the hospital said prawns are actually low in mercury, so they are safe. Just avoid raw street-side preparations and stick to good hygienic restaurants.
I initially panicked thinking seafood has too much mercury and stopped eating completely. Later my doctor cleared up the confusion and said well-cooked prawns are totally safe!