[dr.Ira]

Explanation:

The correct answer is C. According to the guidelines written by the American Academy of Pediatrics in reference to babies born of mothers with group B Strep, if a baby is born at greater than 35 weeks gestation, appears well, but the mother received less than 2 doses of antibiotics (either ampicillin or penicillin) a limited evaluation is indicated. This evaluation includes a CBC, with differential and a blood culture with close clinical observation for at least 48 hours. No antibiotic therapy needs to be started on the baby if all results are normal and the baby continues to appear well.

Close observation only (choice A) would be appropriate for this child only if the mother had received at least 2 doses of antibiotics prior to the delivery. If this had been the case, no laboratory evaluation, and no therapy would be indicated, just close clinical observation for at least 48 hours.

A CBC with differential but no blood culture (choice B) is not a complete work-up for this baby. As stated above, the guidelines indicate that for a baby born to a group B Strep-positive mother who received less than 2 doses of intrapartum antibiotics, both a CBC and blood culture are indicated.

A more complete work-up such as CBC with differential, blood culture, and lumbar puncture (choice D) would be indicated in this baby if there were any signs of sepsis such as prematurity, fever, hypothermia, irritability, or low platelets. If there is a concern of sepsis, after the above tests are done, the baby should be started on empiric antibiotic therapy with ampicillin plus an aminoglycoside or a third-generation cephalosporin. If all the laboratory results and clinical course are unremarkable, and the cultures do not grow, the antibiotic therapy is usually stopped after 48 to 72 hours.

Tachypnea is another sign of sepsis in a neonate. If this baby was tachypneic, a CBC with differential, blood culture, lumbar puncture, and chest x-ray (choice E) would all be indicated. After those tests were completed the baby should be started on empiric antibiotic therapy. If the respiratory distress continues, the baby should be evaluated for possible transfer to the neonatal intensive care unit.