Which antibiotic is preferred for acute cystitis in pregnancy and what precaution is taken?

• A. Ciprofloxacin is preferred; no precautions necessary
• B. Nitrofurantoin or cephalexin in pregnancy; avoid near term depending on guidelines
• C. Amoxicillin is universally safe in all trimesters
• D. Trimethoprim-sulfamethoxazole is recommended in the first trimester

Answer: (B)

Treating acute cystitis in pregnancy requires choosing an antibiotic that is both effective against the common urinary pathogens and safe for the fetus. Nitrofurantoin and cephalexin fit this need because they reach good concentrations in the urine and have well-established safety data in pregnancy. Nitrofurantoin is commonly used in the first and second trimesters, but many guidelines recommend avoiding it near term due to potential neonatal complications if given late in pregnancy. Cephalexin, a cephalosporin, is considered safe throughout pregnancy when the pathogen is susceptible.

In contrast, fluoroquinolones like ciprofloxacin are avoided in pregnancy because of potential fetal cartilage effects; trimethoprim-sulfamethoxazole is avoided especially in the first trimester due to folate antagonism and near term because of risks to the newborn, such as hyperbilirubinemia and kernicterus; amoxicillin may be used in some cases but is less preferred due to resistance patterns and variable efficacy.

So the best answer is nitrofurantoin or cephalexin in pregnancy, with the precaution to avoid nitrofurantoin near term according to guidelines.