My wife is 7 months pregnant and she has UTI, and her doctor recommends that she need to take an antibiotic for a week, my question is, can she not take any antibiotic? Because it's giving her a hard time she's having some allergies on it.. please help..

No, she needs it. Have her talk to her pharmacist about when to take it and with what foods, and so on. She might feel sort of sick (I do when I take them).
She can eat and drink certain foods that help her have a healthy urinary tract and balanced pH, such as asparagus, cranberries, and tons of water. She can keep clean with lots of rinsing after unscented soaps and wearing cotton panties and loose fitting clothing. (Mainly that's what I used to do to prevent yeast infections when I was younger, but it's all part of keeping bacteria out, period, and taking antibiotics often results in yeast infections.)

What kind of allergic reaction is she having? She may just need a different antibiotic.

Okay! well um, so she still need to take an anti-biotic even if it could cause her some allergies and illness? What could be the cost to the baby if she didn't take any? Some of our friends telling us that if she's uncomfortable taking anti-biotic she should stop taking it because it's not safe for her..

If she doesn't get rid of the UTI she could go into preternatural labor. She could end up with a kidney infection or worse.

Again, I ask you, what kind of allergic reaction is she having?