Background The aim of the study was to investigate an effect of perinatal asphyxia and clinical condition on intestinal permeability after birth in premature babies.

Method 45 babies (27–32 weeks) were enrolled in the study. The intestinal permeability was measured by the sugar absorption test on the second day of life and the ratio of lactulose to mannitol (L/M ratio) in the urine was calculated. Perinatal asphyxia was determined using 5 minute Apgar scores and laboratory tests: lactate dehydrogenase (LDH), asparate aminotransferase (AST) and platelet count. Clinical condition was assessed using the clinical risk index for babies score, score for neonatal acute physiology version II (SNAP), SNAP perinatal extension II and lactate acid (LA). The presence of patent ductus arteriosus (PDA) was assessed by colour Doppler echocardiography.

Results Correlation between laboratory markers and the L/M ratio was statistically significant for AST (r  =  0.38, p = 0.009) and LA (r  =  0.54, p = 0.0001). Higher L/M ratios were observed in babies with an LDH level higher than 750 U/l (p = 0.04) and increasing LA level categories defined as: lower than 2.5; 2.51–4.0; 4.01–6.0; more than 6.0 mmol/l (p = 0.02). There was no correlation between Apgar score, illness severity scores and intestinal permeability. There was a significant correlation between a higher L/M ratio and haemodynamically significant PDA defined as LA/Ao ⩾1.4 and the diameter ⩾1.5 mm (p<0.04).

Conclusions Perinatal asphyxia and haemodynamically significant PDA may cause increased intestinal permeability. The measurement of AST, LDH and LA could be useful in assessing the risk of gut barrier dysfunction after birth.