The full blood count in screening asymptomatic infants for early-onset sepsis: A cross-sectional study.

Aim: The full blood count (FBC) is commonly measured as part of a partial septic work-up in asymptomatic infants at increased risk of early-onset neonatal sepsis (EOS). To determine the impact of FBC parameters on infants' subsequent management a retrospective cross-sectional study was performed.

Methods: Infants, born at ≥34 weeks gestation, asymptomatic at birth, undergoing a partial septic work-up and receiving prophylactic antibiotics due to increased risk of EOS in a single centre over a 2-year period, were included. The primary outcome measure was frequency of FBC result impacting on duration of antibiotic therapy. Secondary outcome measures included frequency of FBC parameters outside of the reference range and incidental diagnoses.

Results: In total, 16 726 live-born infants were delivered during the study period. A total of 802 (4.8%) were included. Thirteen infants (1.6%) received a prolonged course of antibiotics due to suspicion for EOS. Two of these infants had elevated white cell counts. All had normal neutrophil counts. In no case did the FBC result influence the decision to prolong the antibiotic course.

Conclusion: In a cohort of 802 infants, asymptomatic at birth and at increased risk of EOS, the FBC result did not impact on the decision to prolong the course of antibiotics for suspicion of EOS.