Importance: High-dose docosahexaenoic acid (DHA), a long-chain polyunsaturated fatty acid, may affect the risk of bronchopulmonary dysplasia (BPD). However, high-level summative evidence supporting such clinical association in very preterm infants is lacking.
Objective: To examine the association between enteral supplementation with high-dose DHA during the neonatal period and the risk of BPD in preterm infants born at less than 29 weeks' gestation.
Data sources: PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials, medRxiv, and ClinicalTrials.gov were searched from inception to August 1, 2022, for eligible articles with no language restrictions.
Study selection: Randomized clinical trials (RCTs) were eligible for inclusion (1) if their interventions involved direct administration of a minimum DHA supplementation of 40 mg/kg/d or breast milk or formula feeding of at least 0.4% of total fatty acids, and (2) if they reported data on either BPD, death, BPD severity, or a combined outcome of BPD and death.
Data extraction and synthesis: Two investigators completed independent review of titles and abstracts, full text screening, data extraction, and quality assessment using the Cochrane Risk of Bias 2.0. Risk ratios (RRs) with 95% CIs were pooled using random-effect meta-analyses.
Main outcomes and measures: Primary outcome was BPD using trial-specific definitions, which was further stratified for RCTs that used a more stringent BPD definition based on systematic pulse oximetry assessment at 36 weeks' postmenstrual age. Other outcomes were BPD, death, BPD severity, or combined BPD and death.
Results: Among the 2760 studies screened, 4 RCTs were included, which involved 2304 infants (1223 boys [53.1%]; mean [SD] gestational age, 26.5 [1.6] weeks). Enteral supplementation with high-dose DHA was associated with neither BPD (4 studies [n = 2186 infants]; RR, 1.07 [95% CI, 0.86-1.34]; P = .53; I2 = 72%) nor BPD or death (4 studies [n = 2299 infants]; RR, 1.04 [95% CI, 0.91-1.18]; P = .59; I2 = 61%). However, an inverse association with BPD was found in RCTs that used a more stringent BPD definition (2 studies [n = 1686 infants]; RR, 1.20 [95% CI, 1.01-1.42]; P = .04; I2 = 48%). Additionally, DHA was inversely associated with moderate-to-severe BPD (3 studies [n = 1892 infants]; RR, 1.16 [95% CI, 1.04-1.29]; P = .008; I2 = 0%).
Conclusions and relevance: Results of this study showed that enteral supplementation with high-dose DHA in the neonatal period was not associated overall with BPD, but an inverse association was found in the included RCTs that used a more stringent BPD definition. These findings suggest that high-dose DHA supplementation should not be recommended to prevent BPD in very preterm infants.