[Urinary tract infection in pregnancy].

Several factors cause urinary tract infection (UTI) to be a relevant complication of the gestational period, aggravating both the maternal and perinatal prognosis. For many years, pregnancy has been considered to be a factor predisposing to all forms of UTI. Today, it is known that pregnancy, as an isolated event, is not responsible for a higher incidence of UTI, but that the anatomical and physiological changes imposed on the urinary tract by pregnancy predispose women with asymptomatic bacteriuria (AB) to become pregnant women with symptomatic UTI. AB affects 2 to 10% of all pregnant women and approximately 30% of these will develop pyelonephritis if not properly treated. However, a difficult-to-understand resistance against the identification of AB during this period is observed among prenatalists. The diagnosis of UTI is microbiological and it is based on two urine cultures presenting more than 10(5) colonies/mL urine of the same germ. Treatment is facilitated by the fact that it is based on an antibiogram, with no scientific foundation for the notion that a pre-established therapeutic scheme is an adequate measure. For the treatment of pyelonephritis, it is not possible to wait for the result of culture and previous knowledge of the resistance profile of the antibacterial agents available for the treatment of pregnant women would be the best measure. Another important variable is the use of an intravenous bactericidal antibiotic during the acute phase, with the possibility of oral administration at home after clinical improvement of the patient. At our hospital, the drug that best satisfies all of these requirements is cefuroxime, administered for 10-14 days. Third-generation cephalosporins do not exist in the oral form, all of them involving the inconvenience of parenteral administration. In view of their side effects, aminoglycosides are considered to be inadequate for administration to pregnant women. The inconsistent insinuation of contraindication of monofluorinated quinolones, if there is an indication, norfloxacin is believed to be a good alternative to cefuroxime. In cases in which UTI prophylaxis is indicated, chemotherapeutic agents are preferred, among them nitrofurantoin, with care taken to avoid its use at the end of pregnancy due to the risk of kernicterus for the neonate.