Researchers have discovered that mothers who have a bacterial infection or colonization during pregnancy may transmit the infection to their babies, causing early-onset neonatal infection.
The study, published in the journal PLOS Medicine, analyzed various medical literature databases for studies conducted between January 1960 and March 2013, in order to identify studies of maternal infection, vertical transmission and neonatal infection.
Researchers from the John Hopkins Bloomberg School of Public Health in Maryland and the Brigham and Women's Hospital in Boston independently assessed the quality of the studies and identified 448 full-text articles. Of these, 83 studies met the criteria to be included in this study, while 67 studies were combined in meta-analysis.
The study authors say they purposefully excluded specific types of non-bacterial infections, tetanus infections, sexually transmitted infections - such as chlamydia, and TORCH infections (Toxoplasmosis, Rubella, Cytomegalovirus, Herpes simplex, Syphilis), because they have varied methods of transmission.
Sevenfold higher risk of infection
Results of the analysis showed that newborn infants of mothers with laboratory-confirmed infection had an odds ratio 6.6 times higher for the development of lab-confirmed infection themselves, compared with newborns of mothers who had no sign of infection.
Newborn infants of mothers with colonization had an odds ratio 9.4 times higher of lab-confirmed infection, compared with newborns of mothers without colonization.
Additionally, the findings revealed that newborns of mothers with risk factors for infection (those who had experienced pre-labor ruptures of membranes, preterm rupture of membranes at earlier than 37 weeks gestation, and prolonged rupture of membranes) had an odds ratio of 2.3 times higher compared with newborns of mothers who did not have these risk factors.
The researchers say:
"We found consistent evidence of higher levels of early-onset neonatal infection among newborns of mothers with bacterial infection or colonization compared to newborns of mothers without infection or colonization."
According to the World Health Organization (WHO), there are estimated to be around 4 million neonatal deaths every year caused by infections, with 1 million of these due to neonatal sepsis and pneumonia alone.
The study authors say that based on their findings, there is great potential to reduce early-onset neonatal infections by focusing on treatments for women with maternal infections, colonization and risk factors for infection.
"Improving identification of clinical signs and risk factors for maternal infection will have more immediate benefits, particularly in resource-limited settings," say the researchers.
"Although this review emphasizes targeting mothers to prevent neonatal infections, a comprehensive package would also focus on early detection of early-onset neonatal sepsis and neonatal treatment to decrease mortality and morbidity from neonatal infections during the first 7 days of life."
In conclusion, the study authors say that further high-quality studies, particularly from areas with high neonatal mortality, are needed to see whether treatment that targets maternal infection or colonization, as well as antibiotic treatment of newborns of high-risk mothers, could prevent a high proportion of early-onset neonatal sepsis.
Written by Honor Whiteman