Acute pyelonephritis in pregnancy: a retrospective study.

OBJECTIVE: To examine the incidence, risk factors, microbial pathogens, and pregnancy outcomes of pregnant women with acute antepartum pyelonephritis.

METHODS: Among all pregnant women admitted to Patan Hospital, Nepal from 14 April 2004 to 13 April 2005, pregnant women with acute pyelonephritis were retrospectively studied. Furthermore, the pregnancy outcomes of these women were compared with those of the general obstetric population received at our hospital during the same time period.

RESULTS: Of 7034 pregnant women delivered at our hospital, 94 cases of acute antepartum pyelonephritis were diagnosed during the study period (incidence: 1.3%). Maternal mean age for the infection was 22 +/- 3.41 years. Acute pyelonephritis was most frequently occurred in nulliparous women (75%), and in the second trimester (60%). Of 94 cases, 62 (65.95%) showed positive urine culture, with the predominating organism Escherichia coli in 81% (50 of 62) of cases. E. coli was found most sensitive to nitrofurantoin (82.1% of cases), followed by ceftriaxone (81.55% of cases), gentamicin (77.01% of cases), ofloxacin (60.57% of cases), and ciprofloxacin (59% of cases). The incidences of low-birthweight babies (14%) and preterm babies (7.81%) in the cases with acute antepartum pyelonephritis were not significantly different compared to that of all births in our hospital during the same period (13% and 8%, respectively; P > 0.05).

CONCLUSIONS: Acute pyelonephritis requiring admission to hospital most frequently occurs in nulliparous women, and in the second trimester. The predominating organism responsible for acute pyelonephritis is E. coli. Ceftriaxone, because of its safety and negligible side-effect, should be the drug of choice for acute antepartum pyelonephritis.