Early-onset neonatal infection, defined as infection in the first 7 days of life, is associated with maternal infection and colonization, a systematic review and meta-analysis by Grace Chan (Johns Hopkins School of Public Health) and colleagues found in this week's issue of PLOS Medicine.
Newborns of mothers with laboratory-confirmed infection had an odds ratio of 6.6 (95%CI 3.9-11.2) for laboratory-confirmed infection themselves compared with newborns of mothers without laboratory-confirmed infection. Newborns of mothers with colonization had an odds ratio of 9.4 (95%CI 3.1-28.5) of laboratory-confirmed infection compared with newborns of non-colonized mothers. Furthermore, newborns of mothers with risk factors for infection (prelabour rupture of membranes, preterm <37 weeks prelabour rupture of membranes, and prolonged rupture of membranes) had an odds ratio of infection of 2.3 (95%CI 1.0-5.4) compared with newborns of mothers without risk factors.
The authors searched medical literature databases through March 2013 for studies meeting their criteria, conducted hand searches, and had two researchers independently identify studies for inclusion. Two researchers also independently assessed study quality. They identified 448 full-text articles of which 83 studies met the criteria to be included in their study and 67 were able to be combined in meta-analyses.
According to the authors, past reviews have evaluated the effect of antibiotics for maternal Group B streptococcal colonization and maternal risk factors of infection on neonatal sepsis, but have not assessed the risks of infection and colonization for other bacterial types. The authors specifically excluded studies of nonbacterial infections, tetanus infections, sexually transmitted infections such as chlamydia or other TORCH (Toxoplasmosis, Rubella, Cytomegalovirus, Herpes simplex, Syphilis) infections, because they have different mechanisms of transmission. Limitations of the systematic review included heterogeneity and high or unclear risk of bias of the included studies.
Discussing the study's implications, the authors state, "The risk of early neonatal infection among women with maternal infections is high and presumably even higher in low-resource settings where most women deliver at home without access to health care. Intrapartum antibiotic prophylaxis could reduce the incidence of maternally acquired early-onset neonatal infections…Development of a simple algorithm that combines clinical signs and risk factors to diagnose maternal infections would be useful in settings where lab facilities (culture or colonization) are not available."
Chan GJ, Lee AC, Baqui AH, Tan J, Black RE (2013) Risk of Early-Onset Neonatal Infection with Maternal Infection or Colonization: A Global Systematic Review and Meta-Analysis. PLoS Med 10(8): e1001502. DOI: 10.1371/journal.pmed.1001502