Antibiotics for a Urinary Tract Infection During Pregnancy

According to the American Pregnancy Association, women between 6 weeks and 24 weeks of pregnancy are at greater risk for a urinary tract infection. A urinary tract infection is a bacterial inflammation of the kidneys, bladder or urethra. It is necessary to treat these infections with antibiotics in order to prevent serious complications during pregnancy. There are several good antibiotic choices that can be used during pregnancy.


According to the American Academy of Family Practitioners, nitrofurantoin, or Macrodantin, is a safe antibiotic to use for a urinary tract infection during pregnancy 12. Nitrofurantoin can achieve high levels of concentration in the urine and has the specific indication for treating urinary tract infections. Women near term should not take nitrofurantoin because it can cause hemolytic anemia in the newborn, but is otherwise safe for use during pregnancy. Diarrhea is a possible side effect of this medication. The American Academy of Family Physicians recommends that pregnant women have a full course of antibiotic treatment that lasts 7 to 10 days 1.


Cephalosporins are good antibiotics for urinary tract infections and are useful in pregnancy 13. This class of drugs is labeled as 1st, 2nd and 3rd generation to refer to the continued development of the antibiotic class. Cephalaxin is a well tolerated cephalosporin that can be taken during pregnancy to treat urinary tract infections 1. Clostridium difficile diarrhea is a known side effect of this medication. Diarrhea symptoms usually will dissipate with the discontinuation of the drug within 24 to 48 hours. Ceftriaxone or cefoxitime can be used when the infection has traveled to the kidneys. The sensitivities of the pathogen to the antibiotic will influence the choice of antibiotic.


Ampicillin historically has been the drug of choice in treating pregnant women with urinary tract infections according to the American Academy of Family Physicians 1. However the pathogen E. coli has become somewhat resistant to ampicillin. Resistance is found in 20 to 30 percent of urinary tract infections caused by E.coli. Ampicillin belongs to the penicillin family and should not be used in patients who are penicillin allergic. Other side effects of ampicillin include anaphylactic reaction, nausea, vomiting and hives.