Of course it is better to avoid any antibiotic treatment when woman is pregnant. However not all diseases can be cured without taking antibiotics. Moreover there are cases when no treating properly the illness may be more dangerous and harmful for the fetus than exposing him to antibiotics.

The main issue is to choose the correct medication which minimizes risks for your baby. Also the safety of particular antibiotics depends not on the drug's characteristic only. The important factors are the dosage, how long you take antibiotic drugs and in which trimester of pregnancy.

It was proven that antibiotics of penicillin group as amoxicillin, ampicillin, don't create any risk to the baby's health when taking during pregnancy. Also cephalosporins (such as cephalexin), and erythromycin are considered to be safe for the unborn child.

However there are antibiotic medications which are totally forbidden during pregnancy. It is streptomycin (used to treat tuberculosis), that can cause hearing loss in your child, and tetracycline (including minocycline, oxytetracycline, and doxycycline), used to treat respiratory infections and acne. If you take tetracycline in the second or third trimester of the pregnancy, it could discolor your developing baby's teeth.

There are antibiotics which physicians are cautious to prescribe during pregnancy. A recent study found an association between two classes of antibiotics generally used to treat urinary tract infections — nitrofuran derivatives and sulfonamides — and rare birth defects. Although there's no direct proof that these antibiotics cause birth defects, additional research is needed. Here it is important to know that if you are taken Macrodantin or Macrobid to prevent the spread of bacteria in your kidneys, you should stop taking these drugs at about 36 weeks (or immediately if you go into premature delivery).

So if antibiotics are the only one way to treat your condition, never adjust the prescription by yourself! Inform immediately your health care provider about your condition, he will ask you to take the necessary tests and only according to the tests' results he will prescribe the safest, most appropriate antibiotic and in a safe dosage for your case.