It is well known that during pregnancy most of the drugs are contraindicated because of the harmful effects to the fetus. It is of great debate whether or not antibiotics can be used during pregnancy and answer to that is same as always, it depends on the type of antibiotic. There are so many types of antibiotics and therefore it takes time to differentiate which to take and what not to. Pregnant women do get sick as sickness is avoidable sometimes and for that antibiotics have to be used.
Antibiotics are mainly used for bacterial infections and during pregnancy it is very important to take care of the drugs that you are using or ought to use as they pose some serious risks to the fetus. There are so many varieties of antibiotics available that many of them has not even be researched enough to be used during pregnancy. Sometimes the drug is not harmful but the high dosage is harmful for the fetus. Therefore dosage should always be considered before using.
Some antibiotics like metronidazole which was earlier said to be harmful as been researched thoroughly and conclusions have been that it is safe to use during pregnancy. Mostly vaginal infections are common in females during pregnancy and therefore now it is safe to say you can use metronidazole. Penicillin is quite safe, for ex. Cephalosporin and erythromycin. They do not cause fetal distress like other drugs that may cause neurological problems and heart problems. Pregnant women suffering from urinary tract infections that is also bacterial infections and for that nitrofurantoin has been used. Nitrofurantoin is safe during pregnancy and doesn't cause harm to the fetus. It can be used up till 36 weeks of pregnancy but not after that. If used after 36 weeks, there may be some serious side-effects to the baby.
Drugs like septra and bactrin should be avoided at all cost. As it is made up of trimethoprim which has a serious side-effect, it causes the blockage of folic acid and as folic acid is very important for the growth of fetus and for the mother, it has been included in the unsafe category of the antibiotics used during pregnany. These drugs are used in urinary tract infection and it may causes birth defects like cleft lip and cleft palate. If for some reason you have to take trimethoprim then please make sure that you take a folic acid tablet daily with a dose of 400 mgs. You have to take extra care of yourself during that period, please ensure that you take your pre-natal vitamins daily. Read the contents of the vitamins and ensure that the dosage of folic acid is minimum 400 mgs.
Do not under any condition take streptomycin and tetracycline. These two drugs are very dangerous causing discolouration of teeth and also cause hearing loss in the fetus. If you still have doubts about what to take and what to avoid, consult your doctor. Doctors know what drug is harmful and will never prescribe something that may harm the fetus.