Enteral Nutrition in Preterm Infants (2022): A Position Paper From the ESPGHAN Committee on Nutrition and Invited Experts.

OBJECTIVES: To review the current literature and develop consensus conclusions and recommendations on nutrient intakes and nutritional practice in preterm infants with birthweight <1800 g. METHODS: The European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) Committee of Nutrition (CoN) led a process that included CoN members and invited experts. Invited experts with specific expertise were chosen to represent as broad a geographical spread as possible. A list of topics was developed, and individual leads were assigned to topics along with other members, who reviewed the current literature. A single face-to-face meeting was held in February 2020. Provisional conclusions and recommendations were developed between 2020 and 2021, and these were voted on electronically by all members of the working group between 2021 and 2022. Where >90% consensus was not achieved, online discussion meetings were held, along with further voting until agreement was reached. RESULTS: In general, there is a lack of strong evidence for most nutrients and topics. The summary paper is supported by additional supplementary digital content that provide a fuller explanation of the literature and relevant physiology: introduction and overview; human milk reference data; intakes of water, protein, energy, lipid, carbohydrate, electrolytes, minerals, trace elements, water soluble vitamins, and fat soluble vitamins; feeding mode including mineral enteral feeding, feed advancement, management of gastric residuals, gastric tube placement and bolus or continuous feeding; growth; breastmilk buccal colostrum, donor human milk, and risks of cytomegalovirus infection; hydrolyzed protein and osmolality; supplemental bionutrients; and use of breastmilk fortifier. CONCLUSIONS: We provide updated ESPGHAN CoN consensus-based conclusions and recommendations on nutrient intakes and nutritional management for preterm infants.

DHA turnover in pregnant women using the natural abundance variation of 13C: a pilot study.

The importance of DHA intake to support fetal development and maternal health is well established. In this pilot study we applied the natural abundance approach to determine the contribution of 200 mg/day of DHA supplement to the plasma DHA pool in 19 healthy pregnant women on a free diet.Women received DHA, from pregnancy week 20 until delivery, from an algal source (N=13, Algae group) or from fish oil (N=6, Fish group) with slightly different content of 13C.We measured plasma phospholipids DHA 13C:12C ratio (reported as δ13C) prior to supplementation (T0), after 10 (T1) and 90 days (T2) and prior to delivery (T3).The δ13C of DHA in algae and fish supplements were -15.8±0.2 mUr and -25.3±0.2 mUr (p<0.001).DHA δ13C in the Algae group increased from -27.7±1.6 mUr (T0) to -21.9±2.2 mUr (T3) (p<0.001), whereas there were not significant changes in the Fish group (-27.8±0.9 mUr at T0 and -27.3±1.1 mUr at T3, p=0.09).In the Algae group 200 mg/day of DHA contributed to the plasma phospholipid pool by a median value of 53% (31-75% minimum and maximum). This estimation was not possible in the fish group.Our results demonstrate the feasibility of assessing the contribution of DHA from an algal source to the plasma DHA pool in pregnant women by the natural abundance approach. Plasma δ13C DHA did not change when consuming DHA of fish origin, with almost the same δ13C value of that of the pre-supplementation plasma δ13C DHA.

Is intravenous fish oil associated with the neurodevelopment of extremely low birth weight preterm infants on parenteral nutrition?

BACKGROUND & AIMS: Preterm infants are at increased risk of long-term neurodevelopmental disabilities (NDD). Long chain n-3 fatty acids play a key role during the development of the central nervous system and some studies in preterm infants showed benefits of docosahexaenoic acid and arachidonic acid supplementation for visual and cognitive development. In recent years fish oil has been added to the fat blend of intravenous (IV) lipid emulsions (LE) but to date scanty data are available on neurodevelopmental outcome of preterm infants that received fish oil containing LE. We studied the effect of fish oil containing IV LE vs standard IV LE on neurodevelopment in a large cohort of preterm infants who received routine parenteral nutrition (PN) from birth. METHODS: We retrospectively reviewed the neurodevelopmental outcome of 477 preterm infants (birth weight (BW): 400-1249 g and gestational age (GA) at birth: 24+0 - 35+6 weeks (W)) admitted to our NICU between Oct-2008 and June-2017, who received routine PN with different LE, with and without fish oil (IV-FO vs CNTR). We compared neurodevelopment at 2 years corrected age by the Bayley III development scale and the incidence of NDD. RESULTS: Demographics, birth data and the incidence of the main clinical short-term outcomes of prematurity were similar in the two groups (IV-FO: n = 178, GA 197 ± 14 days, BW 931 ± 182 g; CNTR: n = 192, GA 198 ± 15 days, BW 944 ± 194 g). No differences were found in maternal demographics nor in parental education between the two groups. Cognitive score was not significantly different between IV-FO and CNTR (92 ± 15 vs 93 ± 13, p = 0.5). No differences were found in motor and language scores, and in the incidence of NDD in the two groups. CONCLUSIONS: Contrary to our hypothesis, the use of fish oil containing LE in a large cohort of preterm infants on routine PN did not result in better neurodevelopment. Large randomized controlled trials powered for neurodevelopment are needed to clarify the impact of the widely used fish oil containing LE on neurodevelopment of preterm infants.

Blood urea in preterm infants on routine parenteral nutrition: A multiple linear regression analysis.

BACKGROUND: Blood urea is considered a marker of amino acid utilization in preterm infants on routine parenteral nutrition. However, the association between blood urea and intravenous amino acid intake remains debated. AIMS: To evaluate the association between blood urea and both nutrition and clinical data, in a large cohort of preterm infants. METHODS: Consecutively admitted preterm infants with a gestational age of less than 32 weeks and a birth weight lower than 1250 g on routine parenteral nutrition from the first hour of life were studied. Clinical and nutrition data collected hourly during the hospitalization were used in multiple linear regression analysis. RESULTS: We studied 674 patients and 1863 blood urea determinations. Blood urea concentration was positively associated with blood creatinine concentration, intravenous amino acid intake, patent ductus arteriosus and respiratory distress syndrome, and negatively associated with intravenous non-protein energy intakes, daily weight change, gestational age, being small for gestational age, antenatal steroids therapy and reverse flow in the umbilical artery (p < 0.001; R = 0.7). CONCLUSIONS: From a nutrition perspective, in our large cohort of small preterm infants blood urea was positively correlated with intravenous amino acid intake and negatively correlated with intravenous non-protein energy intake. This is in line with current knowledge in human physiology and suggest that a reduction of intravenous amino acid intake based on blood urea concentrations was justified.

Does intravenous fish oil affect the growth of extremely low birth weight preterm infants on parenteral nutrition?

BACKGROUND & AIMS: Long chain n-3 fatty acids (n-3 LCPUFA) play a pivotal role during central nervous system development and the provision of docosahexaenoic acid (DHA) is recommended for the preterm infant. However, there are concerns that oral fish oil, which is a good source of DHA, may adversely affect growth of preterm infants, as it decreases arachidonic acid (ARA). It has been about ten years since fish oil was added to the fat blend of intravenous (IV) lipid emulsions (LE) but information on growth and other clinical outcomes of preterm infants is still scarce. We studied the effect of fish oil containing IV LE vs standard IV LE on growth in a large cohort of preterm infants who received routine parenteral nutrition (PN). METHODS: We retrospectively reviewed growth data of 546 preterm infants with a birth weight (BW) < 1250 g consecutively admitted to our NICU between Oct-2008 and Jun-2017 who received PN starting from the first day of life. Individual patients received only one of 5 commercially available IV LE. For the purpose of this study we grouped the patients who received the fish oil containing LE (IV-FO) and those who received conventional LE (CNTR). We compared PN and enteral nutrition (EN) intakes, and growth from birth to 36+0 weeks post-menstrual age (W PMA). RESULTS: Demographics, birth data and the incidence of the main complications of prematurity were similar between the two groups (IV-FO: n = 240, Gestational age (GA) 197 ± 16 d, BW 942 ± 181 g; CNTR: n = 237, GA 199 ± 17 d, BW 960 ± 197 g). No difference was found in PN and EN energy and macronutrient intakes from birth to 36+0W PMA, as well as in the proportion of human milk to infant milk formula. Weight gain from the regained BW to 36+0W PMA was slightly but significantly higher in IV-FO group: 17.3 ± 2.8 and 16.8 ± 2.7 g∙kg-1∙d-1, IV-FO and CNTR respectively (p = 0.03). There was no difference in length gain and head growth nor in body size at 36+0W PMA between the two groups. CONCLUSIONS: The use of IV fish oil did not negatively affect weight gain in a cohort of preterm infants. Large randomized controlled trials are needed to assess the effect of IV fish oil on the complication of prematurity and on selected domains of infant development.

Effects of Arachidonic and Docosohexahenoic Acid Supplementation during Gestation in Rats. Implication of Placental Oxidative Stress.

Arachidonic and docosahexaenoic acids (ARA and DHA) are important during pregnancy. However, the effects of dietary supplementation on fetal growth and oxidative stress are inconclusive. We aimed to assess the effect of high ARA and DHA diet during rat gestation on: (1) ARA and DHA availability in plasma and placenta, (2) fetal growth, and (3) placental oxidative stress, analyzing the influence of sex. Experimental diet (ED) was prepared by substituting soybean oil in the control diet (CD) by a fungi/algae-based oil containing ARA and DHA (2:1). Rats were fed with CD or ED during gestation; plasma, placenta, and fetuses were obtained at gestational day 20. DHA, ARA, and their precursors were analyzed in maternal plasma and placenta by gas chromatography/mass spectrophotometry. Fetuses and placentas were weighed, the proportion of fetuses with intrauterine growth restriction (IUGR) determined, and placental lipid and protein oxidation analyzed. ED fetuses exhibited lower body weight compared to CD, being >40% IUGR; fetal weight negatively correlated with maternal plasma ARA, but not DHA. Only ED female placenta exhibited higher lipid and protein oxidation compared to its CD counterparts; lipid peroxidation is negatively associated with fetal weight. In conclusion, high ARA during gestation associates with IUGR, through placental oxidative stress, with females being more susceptible.

Half-life of plasma phytosterols in very low birth weight preterm infants on routine parenteral nutrition with vegetable oil-based lipid emulsions.

BACKGROUND: Phytosterols in vegetable oil (VO)-based lipid emulsions (LE) likely contribute to parenteral nutrition-associated cholestasis (PNAC) in preterm infants. No characterization of plasma phytosterol half-lives has been done in very low birth weight (VLBW) preterm infants receiving parenteral nutrition (PN) with LE. METHODS: In a prospective cohort study, 45 VLBW preterm infants who received PN underwent serial blood sample measurements of sitosterol (SITO), campesterol (CAMP), and stigmasterol (STIGM). Plasma phytosterol half-lives were calculated from the phytosterol concentrations-decay curves by using a single-compartment model. RESULTS: After the stop of the intravenous LE, study infants had significantly lower plasma total CAMP, STIGM and SITO concentrations. The decay of plasma phytosterol concentrations was monoexponential. Half-life of plasma total CAMP, STIGM and SITO was 13.5 ± 6.9, 10.3 ± 4.5 and 10.3 ± 4.0 days, respectively. Plasma phytosterol half-lives did not correlate with gestational age, birth weight, cumulative phytosterol intakes and plasma conjugated bilirubin. CONCLUSION: VLBW preterm infants on PN with LE had rather long plasma phytosterol half-lives similar to hypercholesterolemic adults and phytosterolemic homozygotes patients. We speculate that the accumulation of phytosterols could contribute to their vulnerability to PNAC. CLINICAL TRIAL REGISTRY: The Ethics Committee of Marche-Italy (DG/469); www.clinicaltrials.gov (identification number NCT02758834).

Effects of early nutrition and growth on brain volumes, white matter microstructure, and neurodevelopmental outcome in preterm newborns.

BackgroundThis study aimed to investigate the effect of nutrition and growth during the first 4 weeks after birth on cerebral volumes and white matter maturation at term equivalent age (TEA) and on neurodevelopmental outcome at 2 years' corrected age (CA), in preterm infants.MethodsOne hundred thirty-one infants born at a gestational age (GA) <31 weeks with magnetic resonance imaging (MRI) at TEA were studied. Cortical gray matter (CGM) volumes, basal ganglia and thalami (BGT) volumes, cerebellar volumes, and total brain volume (TBV) were computed. Fractional anisotropy (FA) in the posterior limb of internal capsule (PLIC) was obtained. Cognitive and motor scores were assessed at 2 years' CA.ResultsCumulative fat and enteral intakes were positively related to larger cerebellar and BGT volumes. Weight gain was associated with larger cerebellar, BGT, and CGM volume. Cumulative fat and caloric intake, and enteral intakes were positively associated with FA in the PLIC. Cumulative protein intake was positively associated with higher cognitive and motor scores (all P<0.05).ConclusionOur study demonstrated a positive association between nutrition, weight gain, and brain volumes. Moreover, we found a positive relationship between nutrition, white matter maturation at TEA, and neurodevelopment in infancy. These findings emphasize the importance of growth and nutrition with a balanced protein, fat, and caloric content for brain development.

Recombinant Bile Salt-Stimulated Lipase in Preterm Infant Feeding: A Randomized Phase 3 Study.

INTRODUCTION: Feeding strategies are critical for healthy growth in preterm infants. Bile salt-stimulated lipase (BSSL), present in human milk, is important for fat digestion and absorption but is inactivated during pasteurization and absent in formula. This study evaluated if recombinant human BSSL (rhBSSL) improves growth in preterm infants when added to formula or pasteurized breast milk. PATIENTS AND METHODS: LAIF (Lipase Added to Infant Feeding) was a randomized, double-blind, placebo-controlled phase 3 study in infants born before 32 weeks of gestation. The primary efficacy variable was growth velocity (g/kg/day) during 4 weeks intervention. Follow-up visits were at 3 and 12 months. The study was performed at 54 centers in 10 European countries. RESULTS: In total 415 patients were randomized (rhBSSL n = 207, placebo n = 208), 410 patients were analyzed (rhBSSL n = 206, placebo n = 204) and 365 patients were followed until 12 months. Overall, there was no significantly improved growth velocity during rhBSSL treatment compared to placebo (16.77 vs. 16.56 g/kg/day, estimated difference 0.21 g/kg/day, 95% CI [-0.40; 0.83]), nor were secondary endpoints met. However, in a predefined subgroup, small for gestational age infants, there was a significant effect on growth in favor of rhBSSL during treatment. The incidence of adverse events was higher in the rhBSSL group during treatment. CONCLUSIONS: Although this study did not meet its primary endpoint, except in a subgroup of infants small for gestational age, and there was an imbalance in short-term safety, these data provide insights in nutrition, growth and development in preterm infants. TRIAL REGISTRATION: ClinicalTrials.gov NCT01413581.

Amino Acid Intake in Preterm Infants.

A large proportion of extremely low-birth-weight infants requires parenteral nutrition for variable lengths of time. Amino acids are the key ingredients of parenteral nutrition. The goal of appropriate amino acid administration is to promote anabolism and normal cellular development in order to limit the incidence of postnatal growth restriction, which is associated with neurodevelopmental delays. The benefits of early amino acid commencement soon after birth are compelling, especially on nitrogen balance, while long-term outcome studies are lacking. Amino acid administration at 2.5 g/kg per day has been shown to be superior to lower intakes; however, the benefits of intakes above 2.5 g/kg per day remain controversial.

Double blind exploratory study on de novo lipogenesis in preterm infants on parenteral nutrition with a lipid emulsion containing 10% fish oil.

BACKGROUND & AIMS: Provision of long chain polyunsaturated fatty acids (LCP) both of the omega-3 and omega-6 families is recommended for preterm infants (PI). Fish oil (FO) contains omega-3 and omega-6 LCP and it is incorporated in the fat blend of the new generation lipid emulsions (LE). Omega-3 LCP have been shown to reduce the expression of genes involved in lipogenesis, which could be important for several organs development. The aim of this study was to ascertain if the use of intravenous FO has an effect on lipogenesis in PI. METHODS: Forty PI were randomized to receive two LE: MSF (50:40:10 Medium Chain Triglycerides (MCT): Soybean oil (SO): FO) or MS (50:50 MCT:SO). We measured plasma lipids on day 7 and the fractional and absolute synthesis rates (FSR and ASR) of cholesterol and of selected fatty acids (FA) after (2)H2O body water labeling. RESULTS: Plasma phospholipids (PL), free cholesterol (FC), and cholesterol esters (CE) concentrations were all lower in MSF than in MS. In spite of lower plasma FC and CE concentrations, cholesterol biosynthesis was similar between the two study groups (FC: FSR 16.0 ± 1.4 vs 14.1  ± 1.1%/d, p = 0.74; ASR 6.8 ± 0.6 vs 7.1 ± 0.6 mg kg(-1) d(-1), p = 0.93; CE: FSR 3.6 ± 0.5 vs 4.2 ± 0.4%/d, p = 0.38; ASR: 3.3 ± 0.4 vs 4.4 ± 0.5 mg kg(-1) d(-1), p = 0.13, in MSF and MS respectively). FSR and ASR of selected FA were, or tended to be, lower in MSF than in MS. ASR of PL palmitate (4.0 ± 0.3 vs 4.8 ± 0.4 mg kg(-1) d(-1), p = 0.045), PL oleate (0.2 ± 0.04 vs 0.4 ± 0.05 mg kg(-1) d(-1), p = 0.02) and CE oleate (0.5 ± 0.1 vs 0.9 ± 0.1 mg kg(-1) d(-1), p = 0.03) were significantly lower in MSF than in MS. There were no differences in plasma TG FA biosynthesis. CONCLUSIONS: Cholesterol biosynthesis was not affected by 10% FO during neonatal parenteral nutrition. Ten percent FO caused a statistically significant reduction in the lipogenesis of selected FA and an overall tendency towards a reduced lipogenesis. The magnitude seems to be limited and the biological significance is unknown. Our data warrant follow-up studies in PI who receive intravenous FO, especially in those infants who receive larger doses than in the present study. Since this trial started in 2007, trial registration was not required.

Growth and fatty acid profiles of VLBW infants receiving a multicomponent lipid emulsion from birth.

OBJECTIVES: Very-low-birth-weight (VLBW) infants are dependent on parenteral nutrition after birth. A parenteral lipid emulsion with a multicomponent composition may improve growth and neurodevelopment and may prevent liver injury, which is often observed in association with long-term parenteral nutrition with pure soybean oil. Our aim was to evaluate the safety and efficacy of a multicomponent lipid emulsion containing 30% soybean oil, 30% medium-chain triacylglycerol, 25% olive oil, and 15% fish oil compared with a conventional pure soybean oil emulsion in VLBW infants. METHODS: We conducted a double-blind randomized controlled trial in VLBW infants randomized to parenteral nutrition with the multicomponent (study group) or pure soybean oil emulsion (control group) from birth at a dose of 2 to 3 g · kg(-1) · day(-1) until the infants were receiving full enteral nutrition. We assessed efficacy by growth rates and measuring plasma fatty acid profiles (representative subset). Safety was evaluated by assessing hematologic and biochemical parameters, potentially harmful phytosterol concentrations (same subset), and clinical neonatal outcome parameters. RESULTS: Ninety-six infants were included (subsets n = 21). The multicomponent emulsion was associated with higher weight and head circumference z scores during admission. Plasma eicosapentaenoic acid and docosahexaenoic acid concentrations were higher in the study group. The hematological, biochemical, and neonatal outcomes were not different between groups, whereas the plasma concentrations of phytosterols were higher in the control group. CONCLUSIONS: The multicomponent lipid emulsion was well tolerated and associated with improved growth and higher plasma fatty acid profiles in VLBW infants in comparison with the pure soybean oil emulsion.

Higher docosahexaenoic acid, lower arachidonic acid and reduced lipid tolerance with high doses of a lipid emulsion containing 15% fish oil: a randomized clinical trial.

BACKGROUND & AIMS: Lipid emulsions containing fish oil, as source of long chain omega 3 fatty acids, have recently became available for parenteral nutrition in infants, but scanty data exist in extremely low birth weight preterms. The objective of this study was to compare plasma fatty acids and lipid tolerance in preterm infants receiving different doses of a 15% fish oil vs. a soybean oil based lipid emulsion. METHODS: Preterm infants (birth weight 500-1249 g) were randomized to receive parenteral nutrition with MOSF (30% Medium-chain triglycerides, 25% Olive oil, 30% Soybean oil, 15% Fish oil) or S (S, 100% Soybean oil) both at two levels of fat intake: 2.5 or 3.5 g kg(-1) d(-1), named 2.5Fat and 3.5Fat respectively. Plasma lipid classes and their fatty acid composition were determined on postnatal day 7 and 14 by gas chromatography together with routine biochemistry. RESULTS: We studied 80 infants. MOSF infants had significantly higher plasma phospholipid Docosahexaenoic acid and Eicosapentaenoic and lower Arachidonic acid. Plasma phospholipids, triglycerides and free cholesterol were all significantly higher in the MOSF-3.5Fat group, while cholesterol esters were lower with MOSF than with S. The area under the curve of total bilirubin was significantly lower with MOSF than with S. CONCLUSIONS: The use of a lipid emulsion with 15% FO resulted in marked changes of plasma long-chain fatty acids. Whether the benefits of increasing Docosahexaenoic acid outweigh the potential negative effect of reduced Arachidonic acid should be further studied. MOSF patients exhibited reduced lipid tolerance at 3.5 g kg(-1) d(-1) fat intake. The trial was conducted between January 2008 and December 2012 so we had not registered it in a public trials registry as it is now required for trials that started after July 2008.

The effect of 5 intravenous lipid emulsions on plasma phytosterols in preterm infants receiving parenteral nutrition: a randomized clinical trial.

BACKGROUND: Elevated plasma phytosterol concentrations are an untoward effect of parenteral nutrition (PN) with vegetable oil-based lipid emulsions (LEs). Phytosterols are elevated in neonatal cholestasis, but the relation remains controversial. OBJECTIVE: The objective was to study the effect of 5 LEs on plasma phytosterols in preterm infants. DESIGN: One hundred forty-four consecutive admitted preterm infants (birth weight: 500-1249 g) were studied. Patients were randomly assigned to receive 1 of 5 different LEs: S [100% soybean oil (SO)], MS [50% medium-chain triglycerides (MCTs) and 50% SO], MSF (50% MCTs, 40% SO, and 10% fish oil (FO)], OS (80% olive oil and 20% SO), or MOSF (30% MCTs, 25% olive oil, 30% SO, and 15% FO). Phytosterols in the LEs and in plasma (on postnatal day 7 and day 14) were measured by gas chromatography-mass spectrometry. RESULTS: Patients in the S group had significantly higher total phytosterol intakes than did the other study groups. On PN days 7 and 14, plasma phytosterol concentrations were highest in the S group and lowest in the MOSF group. Despite similar ß-sitosterol intakes between the MS and MSF groups, plasma concentrations were significantly lower in the MSF than in the MS group. Only 3 patients (2.1%) developed cholestasis: 1 in the MS, 1 in the MSF, and 1 in the MOSF group. No cases of cholestasis were observed in the S and OS groups. CONCLUSIONS: In uncomplicated preterm infants receiving routine PN, we found a correlation between phytosterol intake and plasma phytosterol concentrations; however, cholestasis was rare and no difference in liver function at 6 wk was observed.

Parenteral nutrition of preterm infants with a lipid emulsion containing 10% fish oil: effect on plasma lipids and long-chain polyunsaturated fatty acids.

OBJECTIVE: To compare plasma lipids in preterm infants given a new lipid emulsion containing 10% fish oil, 50% medium-chain triacylglycerols, and 40% soybean oil, compared with a standard preparation containing 50:50 medium-chain triacylglycerols: soybean oil. STUDY DESIGN: Preterm infants weighing <1250 g at birth (n=47) were randomly assigned to receive parenteral nutrition with a fish oil lipid (n=23) or soybean oil (n=24). Plasma lipid classes and plasma and red blood cell fatty acids were determined by gas chromatography in cord blood and on postnatal days 7 and 14. RESULTS: On day 7, the infants receiving fish oil lipid had significantly lower plasma phospholipids, cholesterol esters, and free cholesterol but similar triglyceride concentrations. They also had significantly higher phospholipid docosahexaenoic acid (2.77 ± 0.08 versus 2.46 ± 0.01 mol%, P<.01) and eicosapentaenoic acid (1.58 ± 0.01 versus 0.25 ± 0.01 mol%, P<.01) as well as lower arachidonic acid (10.64 ± 0.29 versus 11.93 ± 0.29 mol%, P<.01) compared with those receiving soybean oil. Similar differences were found in red blood cells. CONCLUSIONS: The fish oil lipid emulsion was well tolerated, and infants receiving fish oil had lower plasma lipids and improved fatty acids status. The effect of these changes on inflammation, growth, and neurodevelopment should be explored.

Synthesis of long-chain polyunsaturated fatty acids in preterm newborns fed formula with long-chain polyunsaturated fatty acids.

BACKGROUND: Docosahexaenoic acid (DHA) and arachidonic acid (AA) are long-chain polyunsaturated fatty acids (LCPs) that play pivotal roles in growth and neurodevelopment. OBJECTIVE: We aimed to quantify the synthesis of LCPs in preterm infants fed infant formula containing LCPs. DESIGN: Twenty-two preterm infants were randomly assigned to either the no-LCP group (fed formula without LCPs; n = 11) or the LCP group (fed formula with LCPs; n = 11). Dietary LCPs had higher (13)C content than did the endogenously synthesized LCPs, which were derived from linoleic and alpha-linolenic acids. The (13)C content of major selected plasma fatty acids was measured by using gas chromatography-isotope ratio mass spectrometry at birth and at age 1, 3, and 7 mo. Absolute LCP synthesis and the percentage of LCP synthesis relative to dietary intake were calculated. RESULTS: Percentage AA synthesis was 67.2 +/- 7.8%, 35.9 +/- 9.8%, and 29.0 +/- 10.3%, and that of DHA was 41.7 +/- 14.9%, 10.5 +/- 8.1%, and 7.4 +/- 6.2% at 1, 3, and 7 mo old, respectively. Absolute AA synthesis was 26.7 +/- 4.2, 14.4 +/- 3.9, and 11.6 +/- 4.1 mg x kg(-1) x d(-1) and that of DHA was 12.6 +/- 4.5, 3.2 +/- 2.5, and 2.3 +/- 1.9 mg x kg(-1) . d(-1) at 1, 3, and 7 mo old, respectively. AA and DHA synthesis decreased significantly (P < 0.01) with time, and AA synthesis was significantly (P < 0.01) greater than DHA synthesis. CONCLUSIONS: By this novel approach, we measured endogenous LCP synthesis in infants receiving dietary LCPs over long periods. By age 7 mo, LCP synthesis was dramatically lower in preterm infants fed LCPs.

Endogenous pulmonary surfactant metabolism is not affected by mode of ventilation in premature infants with respiratory distress syndrome.

OBJECTIVE: To determine if high frequency oscillatory ventilation (HFOV) decreases surfactant production in premature infants with respiratory distress syndrome (RDS). STUDY DESIGN: We randomized 19 infants <28 weeks of gestation to either HFOV (n = 8) or conventional ventilation (CV, n = 11) at 24 hours of life. After a 24-hour continuous infusion of uniformly labeled carbon 13 glucose (U-(13)C(6)) glucose, we measured (13)C enrichment in surfactant phosphatidylcholine (PC) in tracheal aspirate samples using gas chromatography/mass spectrometry. We calculated the fractional synthetic rate (FSR) of surfactant PC from labeled glucose and its half-life of clearance (T(1/2)). RESULTS: FSR did not differ between groups (4.7% +/- 2.7%/day CV vs 4.2% +/- 3.1%/day HFOV, P =.7). T(1/2) was 79 +/- 18 hours in the CV group and 76 +/- 23 hours in the HFOV group (P =.7). Neither degree of ventilatory support nor supplemental oxygen exposure correlated with surfactant metabolic indices. Three of 4 infants who died from RDS within the first month of life had a shorter T(1/2) than 14 of 15 infants who survived. CONCLUSION: Surfactant metabolism is similar in preterm infants ventilated with HFOV and CV. Shortened surfactant half-life may characterize a subset of preterm infants with lethal RDS.