Early-onset neonatal sepsis in Dhaka, Bangladesh: risk associated with maternal bacterial colonisation and chorioamnionitis

OBJECTIVE To estimate the risk of early-onset neonatal sepsis among newborns of mothers with chorioamnionitis and/or bacterial colonisation in Dhaka. METHODS We conducted a cohort study at a maternity centre following 600 mother-newborn pairs. Women with a positive bacterial vaginal culture or positive Group B streptococcus (GBS) rectal culture during labour were classified as colonised. Women with placental histopathology demonstrating signs of maternal or foetal inflammation were classified as having chorioamnionitis. Newborns were followed over the first 7 days of life. The primary outcome measure was physician or community health worker diagnosis of neonatal sepsis following modified World Health Organization Integrated Management of Childhood Illnesses criteria. Survival analysis was conducted with non-parametric, parametric and semiparametric models. RESULTS Of the 600 mother-newborn pairs, 12.8% of newborns were diagnosed with early-onset sepsis. Five hundred and forty-three women had both colonisation and chorioamnionitis data, 55.4% of mothers were non-exposed, 31.7% were only colonised and 12.9% had chorioamnionitis regardless of colonisation status. After adjusting for birthweight, sex, maternal characteristics and wealth, newborns of only colonised mothers developed sepsis 63% faster and had a 71% higher risk of developing sepsis than their non-exposed counterparts (RT = 0.37, 95% CI 0.14-1.03; RH = 1.71, 95% CI 1.00-2.94). Newborns of mothers with chorioamnionitis developed sepsis 74% faster and had a 111% higher risk of developing sepsis (RT = 0.26, 95% CI 0.07-0.94; RH = 2.11, 95% CI 1.06-4.21). CONCLUSIONS Newborns born to mothers with colonisation or chorioamnionitis developed sepsis faster and were at higher risk of developing sepsis in Dhaka.