What is the best treatment options for a pregnant woman with uti in 1st, 2nd n 3rd trimester?

Antibiotics : Bladder infections are treated with antibiotics. Your doctor will know which ones are safe for use. Ampicillin and Nitrofurantoin are two commonly used ones.

UTI: During pregnancy you want to be sure that the antibiotic used will not hurt the fetus. Stay away from tetracyclines and fluorinated quinolones. Best would be either an oral penicillin derivative (amoxicillin, etc.) or an oral cephalosporin, but Bactrim (sulfamethoxazole and trimethoprim) or septra (trimethoprim/sulfamethoxazole) is probably ok although in fda category c, meaning do not use unless benefits outweigh risks.