The Effect of Neonatal Feeding Modalities on Splanchnic Oxygenation

OBJECTIVES: The main purpose of this study was to evaluate the impact of drip versus intermittent feeding on splanchnic oxygenation in preterm infants with intrauterine growth restriction (IUGR). The second objective was to assess the relationship between fetal splanchnic circulation parameters and splanchnic oxygenation during the first week of life.

METHODS: A single-center, prospective, randomized study with 51 fetuses/infants was conducted. Fetal Doppler measurements including umbilical artery, middle cerebral artery, and superior mesenteric artery (SMA) were recorded in IUGR fetuses. After preterm delivery the infants were randomly assigned to one of two feeding modalities: drip (3-hour continuous) or intermittent (bolus in 10 minutes). Continuous regional splanchnic saturation (rSO2S) monitoring was carried out during first week of life, simultaneously with continuous oxygen arterial saturation (SaO2) monitoring and the infants' fractional oxygen extractions (FOE) were calculated. These parameters were evaluated as means on a daily basis for the first week of life, as well as pre-prandial and post-prandial measurements on the seventh day.

RESULTS: Fetal Doppler flow velocimetry disturbances were present in 72.5% of the study cohort. The Drip (26 infants) and Intermittent (25 infants) groups were similar in demographic and clinical characteristics, as well as the prevalence of feeding intolerance and necrotizing enterocolitis. During the first week of life, there was no difference in daily mean rSO2S and FOE values between the Drip and Intermittent groups, whereas unfed infants had mostly lower rSO2S values. Pre-prandial and post-prandial rSO2S values remained stable in both groups. Also, no association was detected between fetal splanchnic circulation parameters and neonatal splanchnic oxygenation. RSO2S values were strongly correlated to gestational age and birth weight. During the whole week, except for the first two days, infants with umbilical catheters had significantly lower rSO2S values than infants without.

CONCLUSIONS: Our data suggests that the key factor in splanchnic oxygenation is feeding, not the feeding modality. In addition, the umbilical vein catheter had a negative impact on splanchnic oxygenation.

Study design This single-center prospective randomized study was conducted in a university hospital between 1 January 2019-1 October 2021. This work has been supported by Eskisehir Osmangazi University Scientific Research Projects Coordination Unit under grant number 61690618-604.99-E.61140. This study was conducted in conformity with the principles and regulations of the Helsinki Declaration. The Institutional Ethics Committee approved the study (No: 80558721-050.99-E.105607) and informed consent forms were received from all parents/legal guardians of each fetus/infant before inclusion in the study.

Study Cohort The inclusion criteria were that the parents agreed to participate in the study and that Doppler measurements could be performed in fetuses with IUGR and following preterm birth (GA\<37 weeks) with no enteral nutrition prior to enrolment. The infants with chromosomal or major congenital abnormalities that may influence the ability to monitor the splanchnic bed (congenital heart defects, abdominal wall defects, or congenital diaphragmatic hernia), inherited metabolic diseases, hydrops fetalis, TORCH infection, multiorgan failure, infants with spontaneous intestinal perforation, infants with skin lesions at the site of sensor placement and infants who were hospitalized shorter than 7 days because of discharge or death were excluded from the study.

Eligibility Criteria:
Inclusion Criteria:

* Doppler measurements must be performed in fetuses with IUGR
* Preterm infants (GA\<37 weeks) with IUGR who were evaluated by Doppler ultrasound were eligible for the study
* These preterm infants must have no enteral nutrition prior to enrolment.

Exclusion Criteria:

* Chromosomal or major congenital abnormalities that may influence the ability to monitor the splanchnic bed (congenital heart defects, abdominal wall defects, or congenital diaphragmatic hernia)
* Inherited metabolic diseases
* Hydrops fetalis
* TORCH infection
* Multiorgan failure
* Infants with spontaneous intestinal perforation
* Infants with skin lesions at the site of sensor placement
* Infants who were hospitalized for shorter than 7 days because of discharge or death