Because all children became seropositive after revaccination, the age of administration can be based on the convenience of vaccine scheduling. However, in view of the apparent decline in rubella antibodies at 11 to 13 years, future studies of rubella vaccination should address the issue of whether earlier boosting leads to greater susceptibility at the time of reproductive age.

ABSTRACT. Objectives. To determine: (1) whether a lumbar puncture (LP) is indicated in asymptomatic fullterm newborns delivered by mothers at risk of intrapartum sepsis; and (2) whether gentamicin improves bacterial coverage for such newborns when used with ampicillin.Design. A retrospective chart review from 1987 through 1993 of all newborns with positive blood and/or cerebrospinal fluid cultures in the first 7 days of life.Methods. Pregnant women were screened in the second trimester for group B streptococci and given ampicillin during labor if two or more risk factors were present: group B streptococci colonization, maternal fever or leukocytosis, rupture of membranes at more than 18 hours, foul-smelling amniotic fluid, and fetal tachycardia. After sepsis evaluation (LP, blood culture, white blood cell count, and differential), asymptomatic infants received ampicillin and gentamicin for 48 to 72 hours unless cultures grew pathogens.Results. Of approximately 24 452 full-term births in 7 years, 7% (1712) had evaluations for symptoms of sepsis, and 14% (3423) were asymptomatic but had evaluations for maternal risk factors. There were 11 cases of meningitis, all involving symptomatic newborns; 10 of these 11 had positive blood cultures for the same organism. In asymptomatic infants, none of the 3423 had meningitis (95% confidence interval, 0 to 0.0008), although 35 grew contaminants. Of 73 pathogens isolated from blood or cerebrospinal fluid, 7 (9.5%) were resistant to ampicillin. Addition of gentamicin provided coverage for only 2 of these 7 pathogens. Of 5135 infants who received ampicillin and gentamicin, only 2 required gentamicin for improved coverage.Conclusions.(1) LP is unnecessary in asymptomatic full-term newborns. (2) Empiric coverage for asymptomatic newborns with maternal risk factors need not include gentamicin at all hospitals, because it only improved the coverage of ampicillin alone from 90% to 93% of pathogens, but it exposed more than 5000 infants to the side effects of gentamicin. (3) The presence of leukopenia (<5000 white blood cells/mm 3 ) is highly predictive of bacteremia. Pediatrics 1997;99(4). URL: http://www. pediatrics.org/cgi/content/full/99/4/e10; newborn, lumbar puncture, meningitis.