Infection in the fetus and neonate

Infection of the fetus and newborn infant poses unique challenges in both diagnosis and management. Transplacental infections can result in fetal loss/abnormalities and intrauterine growth restriction. Such infections usually persist and may be evident or asymptomatic at birth. Some of the latter cases may develop late symptoms such as Toxoplasma choroidoretinitis. Diagnosis remains difficult because clinical features lack specificity and because the immaturity of the neonatal immunity and the existence of maternal antibodies make serology hard to interpret. However, increasing use of polymerase chain reaction analysis and related techniques has resulted in increasingly accurate diagnosis. Interventions to reduce the burden of infection include maternal avoidance of high-risk foods, mass immunization (rubella), antenatal and post-natal treatment (HIV, Toxoplasma), neonatal immunization (hepatitis B) and avoidance of breast-feeding (HIV). Early-onset neonatal sepsis (EONS) is almost exclusively caused by organisms acquired from the maternal genital tract and carries high mortality and morbidity. Vaginal antiseptic treatments have proved disappointing in preventing infection. After pre-term rupture of membranes, prophylactic antibiotic administration to the mother reduces the incidence of EONS. In any woman known to carry group B Streptococcus, intrapartum antibiotics can greatly reduce the incidence of EONS caused by this organism. Late-onset neonatal sepsis and acquired neonatal viral infections are usually acquired horizontally from the environment. The range of organisms is wide. Attention to infection control procedures in the nursery and judicious use of antibiotics to reduce the risk of emergence of antibiotic resistant bacterial or fungal infections are important.