Impact of trimester on morbidity of acute pyelonephritis in pregnancy

OBJECTIVE: We sought to compare maternal and neonatal morbidity as well as obstetric outcomes associated with pyelonephritis in pregnancy during the first compared to the second/third trimester. STUDY DESIGN: A retrospective cohort analysis was performed of all pregnant women admitted to a single tertiary care hospital between January 2004 and June 2007 with pyelonephritis. The primary outcome was length of hospitalization. The study had 80% power to detect a 1-day difference in length of stay. RESULTS: In all, 219 cases of acute pyelonephritis were identified: 23 diagnosed in the first trimester and 196 in the second/third trimester. Women were hospitalized for a median of 4 days in both the first (range, 2-7) and second/third (range, 2-9; P = .6) trimesters. Neonatal and obstetric outcomes were not statistically significant. CONCLUSION: Maternal morbidity and obstetric outcomes do not differ between first-and second-/third-trimester pyelonephritis. First-trimester pyelonephritis should be aggressively treated to prevent adverse outcomes.