Lung function in preterm infants at 3 months corrected age after neonatal LC-PUFA supplementation

To test the hypothesis that long-chain polyunsaturated fatty acid (LC-PUFA) supplementation improves lung function at 3 months corrected age (CA) compared with standard treatment in very preterm infants. We also aimed to investigate the association between bronchopulmonary dysplasia (BPD), longitudinal growth, and lung function at 3 months CA.

A secondary analysis from the ImNuT trial, in which 121 infants with gestational age <29 weeks were randomized to a daily supplement with arachidonic acid (ARA) and docosahexaenoic acid (DHA) (ARA:DHA group) or MCT-oil (control group) from birth up to 36 weeks postmenstrual age (PMA). Lung function was assessed at 3 months CA by tidal flow volume loops and the outcomes were the ratio of time to peak tidal expiratory flow to expiratory time (t_PTEF /t_E ) and tidal volume (V_T ) per body weight (mL/kg).

Thirty-nine infants in the ARA:DHA group versus 51 in the control group had a successful lung function test. There was no mean difference (MD) in t_PTEF /t_E ratio (MD: 0.01, 95% confidence interval [CI]: -0.04 to 0.05; p = .77) or V_T (MD: 0.09 mL/kg, 95% CI: -0.79 to 0.62; p = .81) between the study groups. The multivariable regression model showed that BPD was associated with t_PTEF /t_E ratio ≤ 0.25 (p = .03) and that an increase in z score for length after 36 weeks PMA correlated positively with V_T (mL/kg) (p = .03).

Neonatal LC-PUFA supplementation did not improve lung function at 3 months CA in very preterm infants. BPD was independently associated with reduced lung function, while improved linear growth correlated with higher tidal volumes.