From memory -only One reterospective study with large numbers from Harbor-UCLA showed foul smelling as a minor risk. In this old study (~25-30 years back) they assigned 1, 2 or 3 number to low , mod and high risk facors and patient above certains numbers (total) were treated.
Dr Hodgeman from LACounty - USC used to say "anerobic infections cause foul smelling but not neonatal sepsis and GBS-Ecoli do not smell"