The use of blood counts and blood cultures to screen neonates born to partially treated group B Streptococcus-carrier mothers for early-onset sepsis: is it justified?

BACKGROUND

No clear recommendations exist regarding the approach to evaluate neonates born to partially treated group B Streptococcus (GBS)-carrier mothers for early-onset GBS (EO-GBS) sepsis.

OBJECTIVE

To determine the yield and drawbacks of screening, all neonates born to GBS-carrier mothers who received only one dose of IV antibiotic, less than 4 hours, before delivery (partially treated).

METHODS

A retrospective analysis was performed of all complete blood counts (CBCs) and blood cultures obtained from infants born during the period 2005 to 2009 to GBS-positive screened mothers treated with only one dose of antibiotic prior to delivery. A review was conducted of all neonatal EO-GBS sepsis cases during the study period.

RESULTS

: Of 5845 GBS-carrier mothers, 1648 (28%) received only one dose of antibiotic less than 4 hours before delivery. We traced the CBCs and blood cultures, which were taken from 1413/1648 (86%) infants after birth. In 234 (18%) of these 1413 neonates, a second CBC sample was taken due to abnormal result of the CBC (leukocytosis, leukopenia, or thrombocytopenia) or secondary to technical failure in obtaining the blood. None of the blood cultures taken in that screening protocol was GBS positive, but in 10 cases contamination with coagulase-negative Staphylococcus was reported. During the study period, EO-GBS sepsis was diagnosed in 11 neonates; all had clinical symptoms upon presentation.

CONCLUSIONS

The use of CBC and blood culture to screen neonates born to GBS-carrier mothers who received only one dose of IV antibiotic before delivery led to a negligible clinical yield and a high rate of technical failure. Although these findings are in line with the recent change in the Centers for Disease Control guidelines, they put in question the cost of this practice in terms of neonatal pain and parental anxiety.