Background: Necrotizing enterocolitis (NEC) is the most common emergency of the gastrointestinal tract occurring in the neonatal period. There have been published reports which suggest that oral immunoglobulins IgA and IgG produce an immunoprotective effect in the gastrointestinal mucosa. This systematic review was undertaken to clarify the issue.
Objectives: To assess whether oral immunoglobulin administered to preterm and low birth-weight neonates reduces the incidence of necrotizing enterocolitis without adverse effects.
Search strategy: The databases MEDLINE, CINAHL, EMBASE (1966 to October 26, 2003) and the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 3, 2003) were searched. Proceedings of the Perinatal Society of Australia and New Zealand were hand searched. The computer neonatal discussion site 'Nicu Net' was also used. Additionally, all references in the identified trials were checked and authors were contacted to request any additional published or unpublished data. No new trials were identified.
Selection criteria: All randomised or quasi-randomised controlled trials where oral immunoglobulins were used as prophylaxis against necrotizing enterocolitis in preterm (<37 weeks gestation) and/or low birth-weight (<2500 gms) neonates.
Data collection and analysis: The procedures of the Cochrane Neonatal Review Group (CNRG) were used. The two reviewers independently assessed the trials for their methodological quality and subsequent inclusion in the review. Relative risk (RR), risk difference (RD), and number needed to treat (NNT) were used in the analysis.
Main results: Five studies on oral immunoglobulin for the prevention of necrotizing enterocolitis were identified of which three met the inclusion criteria. In this review of the three eligible trials (including a total of 2095 neonates) the oral administration of IgG or an IgG/IgA combination did not result in a significant reduction in the incidence of definite NEC [RR 0.84 (95% CI 0.57, 1.25), RD -0.01 (95% CI -0.03, 0.01)], suspected NEC [RR 0.84 (95% CI 0.49, 1.46), RD -0.01 (95% CI -0.02, 0.01)], need for surgery [RR 0.21 (95% CI 0.02, 1.75), RD -0.03 (95% CI -0.06, 0.00)] or death from NEC [RR 1.10 (95% CI 0.47, 2.59), RD 0.00 (95% CI -0.01, 0.01)].
Reviewer's conclusions: Based on the available trials, the evidence does not support the administration of oral immunoglobulin for the prevention of NEC. There are no randomised controlled trials of oral IgA alone for the prevention of NEC.