The commonest pathogen responsible for acute pyelonephritis in pregnancy is:
Escherichia coli
Klebsiella pneumoniae
Proteus mirabilis
Pseudomonas aeruginosa
E. coli is the common bacteria responsible for acute pyelonephritis in pregnancy It also causes asymptomatic bacteriuria. Urinary tract infection in pregnancy is a risk factor for threatened aboion, chorioamnionitis, preterm labor, IUGR.
Medical Illness Complicating Pregnancy