Superior Mesenteric Artery Blood Flow in Parenterally Fed Versus Enterally Fed Preterm Infants.

Objectives: The aim of the study was to compare superior mesenteric artery (SMA) flow in premature infants with parenteral and enteral nutrition.

Methods: A prospective study was conducted on 2 groups of preterm infants with gestational age of 280/7 to 366/7 weeks: group 1 did not qualify for early enteral feeds and received parenteral nutrition (PN), and group 2 received early enteral feeding. SMA peak systolic velocity (PSV), end diastolic velocity (EDV), and pulsatility index (PI) were measured using Doppler ultrasound before starting feeds at day 1 and at day 5.

Results: The study recruited 40 infants; 20 in each group. At baseline, PSV, EDV, and PI did not differ between groups. At day 5, enteral nutrition was associated with significant increases in PSV (91.53 ± 29.15 vs 65.49 ± 19.18, P = 0.003) and EDV (15.91 ± 7.01 vs 11.65 ± 5.58, P = 0.026) and a decrease in PI (1.28 ± 0.40 vs 2.48 ± 0.83, P < 0.001). Regression analysis to control for confounders showed enterally fed infants to have increased PSV (adjusted odds ratio [aOR] = 25.45; 95% confidence interval [CI]: 8.53-42.38, P = 0.004) and EDV (aOR 8.630; 95% CI: 2.987-14.273, P = 004) and decreased PI (aOR = -1.133; 95% CI: -1.603 to -0.664, P < 0.001). Infants in the PN group later developed more frequent feeding intolerance when compared with the enterally fed group (65% vs 15%, respectively, P < 0.001).

Conclusions: In preterm neonates, early EF is associated with increased SMA blood flow, decreased vascular intestinal resistance, and less frequent incidence of feeding intolerance.