Seven studies met the authors' inclusion criteria.
Five studies were used to determine the effect of antibiotics on mortality (total number of participants: 212 treated and 217 control).
Five studies were used to determine the effect of antibiotics on sepsis (total number of participants: 254 treated and 254 control).
Six studies were used to determine the effect of antibiotics on RDS (total number of participants: 251 treated and 258 control).
Five studies were used to determine the effect of antibiotics on IVH (total number of participants: 210 treated and 217 control).
Five studies were used to determine the effect of antibiotics on NEC (total number of participants: 210 treated and 217 control).
Antibiotic therapy significantly reduced the risk of neonatal sepsis by 68% (OR 0.32, 95% CI: 0.16, 0.65) and IVH by 50% (OR 0.50, 95% CI: 0.28, 0.89).
Antibiotic treatment did not have a significant effect on neonatal mortality (OR 0.92, 95% CI: 0.46, 1.81), RDS (OR 0.84, 95% CI: 0.85, 1.22), or NEC (OR 1.27, 95% CI: 0.61, 2.62).
Statistical testing for differences between the studies showed that homogeneity existed for each of the five outcome measures