Antibiotic Safety

A normal, healthy pregnancy is sometimes complicated by an infection that requires treatment with antibiotics. Everything from a routine urinary tract infection to a sexually transmitted disease can put your and your baby's health at risk. However, an antibiotic's safety depends not only on the characteristic of the drug itself, but also how much is taken, for how long, and during what stage of pregnancy.

Antibiotics are often given to women during labor if they have tested positive for Group B Strep, if they are in preterm labor, or if their membranes rupture and the baby is not delivered within 18 hours. Pregnant women may also receive antibiotics if they have a high fever, if the fetus's heart rate exceeds 160 beats per minute, or if the amniotic fluid is malodorous.

Antibiotics may increase the likelihood that your baby develops a fungal or yeast infection or experiences diarrhea, which can lead to dehydration. While these conditions do not pose a risk to healthy full term babies, they can be dangerous for stressed or preterm babies.

In a study reported in the American Journal of Obstetrics and Gynecology, the babies of mothers who received some type of antibiotic during their pregnancy or labor were less able to fight off infection, and almost half of them were resistant to ampicillin, a penicillin-like antibiotic. However, antibiotics should not be withheld if the woman needs them. In some cases, the risk of not treating a condition with antibiotics outweighs the risk of exposing the fetus to the medication. You should always discuss the situation with your doctor, and weigh the risks and benefits to determine what is best for you and your baby.

Some antibiotics are safe to take while you are pregnant, some pose a risk to the fetus, and many fall somewhere in between depending on when and how much you take. There are dozens of types of antibiotics, but some of the most common that are considered safe to take during pregnancy include:

• Penicillin

• Cephalosporin

• Erythromycin

• Metronidazole - Some experts used to suspect a link between metronidazole and birth defects. However, new studies have not supported this theory and it is considered safe in most cases.

Some types of antibiotics that should be avoided during pregnancy include:

• Streptomycin - used to treat tuberculosis. This can cause hearing loss in your baby.

• Tetracycline - used to treat acne and respiratory infections. If taken in the first trimester, there is a small risk of birth defects. However, if taken in the second or third trimester, it may discolor your baby's teeth.

• Trimethoprim - used to treat urinary tract infections. It blocks the effects of folic acid. If you must take this antibiotic during your pregnancy, be sure to take your daily prenatal vitamin as well.

Always let your doctor know you are pregnant before he or she prescribes any medication, and check with your obstetrician or midwife before taking any new medication prescribed by another physician.