[Prenatal and perinatal infections--problems for the practicing pediatrician: group B streptococci, varicella, toxoplasmosis].

A practical approach is reported for the care of the neonate born to a mother infected/colonized during pregnancy by group B streptococcus, varicella-zoster virus or Toxoplasma gondii. Starting from clinical situations, an attempt is made to work out evidence based recommendations using an overview of the current literature. GROUP B STREPTOCOCCI: Relevant factors for the treatment of infants born to colonized mothers are clinical symptoms, gestational age, additional risk factors (such as premature rupture of membranes or maternal fever) and intrapartum antibiotics. Postnatal antibiotic prophylaxis and laboratory screens failed the test of controlled trials. Transfer to a neonatology unit is recommended for symptomatic term and all preterm infants. Asymptomatic term infants should be carefully monitored during the first 48 hours for signs of respiratory, circulatory or thermoregulatory compromise. VARICELLA: In the case of maternal varicella near term, delaying delivery for one week will lower the risk of severe neonatal varicella. The postnatal administration of varicella-zoster-immunoglobulin to the neonate is supported by some (if limited) evidence from the literature in the case of maternal eruption between 7 days before and 2 days after delivery. In newborns of mothers with eruption appearing later immunoglobulin is often recommended, though no supporting clinical evidence is available. There are no data to justify the use of immunoglobulin after exposure during pregnancy in order to prevent pneumonia in the pregnant patient, but there are preliminary indications that its application could lower the risk of congenital varicella syndrome (2% between 13 and 20 weeks). The use of immunoglobulin in very low birth weight infants after nosocomial exposure is generally recommended but efficacy data are lacking. TOXOPLASMOSIS: The practical approach depends on clinical findings in the newborn and laboratory results during pregnancy and after birth. Examination of the newborn should include fundoscopy, cranial sonography and, in cases of documented infection, lumbar puncture. Serology from cord blood comprises assays for IgG, IgM and if possible IgA/IgE. If available, demonstration of the parasite by culture or PCR can be helpful. All infants with documented congenital toxoplasmosis should be treated for a minimum of 12 months. In the case of suspected toxoplasmosis the child should be treated as long as the suspicion persists. The prognosis after consequential therapy is less bleak than previously reported for untreated children even in seriously symptomatic patients.