Infection with Mycoplasma hominis in postpartum fever

A follow-up of 535 patients after vaginal delivery showed that 9% had a fever of 37.7 degrees C or greater, and 2% had a fever of 38 degrees C or more, on two days. The commonest cause of both categories of fever was Mycoplasma hominis infection as defined by a fourfold or greater rise in mycoplasmacidal antibody titre. Among women for whom sera were available this agent caused 50% (14/28) of all fevers and 71% (5/7) of the higher fevers. Absence or low titre (< 1:8) of antibody against M. hominis was the strongest single predictor of otherwise unexplained fever (16/40 patients with low antibody titre were febrile vs 7/50 with high antibody titre, p < 0.01). Among women with absent or low antibody titres, both rise in titre of antibody to this organism and lochial colonisation by it were significantly associated with fever (p < 0.001, p < 0.025, respectively). Standard microbiological and clinical techniques identified probable causes in only 18% (5/28) of all fevers and 29% (2/7) of higher fevers. Patients who had postpartum infection caused by M. hominis remained in hospital 31% longer than the non-infected patients (4.57 vs 3.49 days, p < 0.001). Low antibody to and lochial colonisation with M. hominis occurred together in 17% of patients, who accounted for 71% of all higher fevers. Since these risk factors for postpartum fever can be identified before delivery, prophylactic measures applied selectively to women with these risk factors may prevent a large proportion of postpartum fevers and the excess hospital stay associated with them.