Clinical Risk Factors Associated With Peripartum Maternal Bacteremia

To evaluate risk factors associated with maternal bacteremia in febrile peripartum women.

We performed a case-control study of women with fevers occurring between 7 days before and up to 42 days after delivery of viable neonates at two academic hospitals. Women with positive blood cultures were matched with the next two febrile women meeting inclusion criteria with negative blood cultures in the microbiology data without other matching parameters. We compared maternal and neonatal characteristics and outcomes between women in the case group and those in the control group with univariate analysis. We then used logistic regression to examine the association between clinical characteristics and maternal bacteremia.

After excluding blood cultures positive only for contaminants, we compared 115 women in the case group with 285 in the control group. Bacteremic women were more likely to experience their initial fever during labor (40.9% compared with 22.8%, P<.01) and more likely to have fever at or above 102°F (62.6% compared with 31.6%, P<.01). These associations persisted in the adjusted analysis: multiparity (adjusted odds ratio [OR] 1.75, 95% CI 1.07-2.87), initial fever during labor (adjusted OR 2.82, 95% CI 1.70-4.70), and fever at or above 102°F (adjusted OR 3.83, 95% CI 2.37-6.19). In an analysis restricted to neonates whose mothers had initial fevers before or in the immediate 24 hours after delivery, neonates born to women in the case group had higher rates of bacteremia compared with those born to women in the control group (9.0% compared with 1.3%, P<.01). Eight of the nine bacteremic neonates born to bacteremic mothers (89%) grew the same organism as his or her mother in blood culture.

Maternal bacteremia is associated with multiparity, initial fever during labor, and fever at or above 102°F; however, 37.5% of cases of bacteremia occurred in women with maximum fevers below this threshold. Obstetricians should maintain a heightened suspicion for an infectious source of fever in women with these clinical characteristics.