Background Two risk factors for severe retinopathy of prematurity (ROP) in extremely preterm infants are thrombocytopenia and low levels of arachidonic acid (AA) and docosahexaenoic acid (DHA). To date, these risk factors have not been linked. Method Infants born < 28 weeks gestational age (GA) from 2016 to 2019 were randomized to postnatal enteral AA/DHA supplementation or standard care (controls). Levels of AA and DHA, platelet counts ( < 100 x 109/L defined as thrombocytopenia) and platelet-related proteins in the infants' first four weeks of life were evaluated for their association with severe ROP. Results The mean birthweight of 178 included infants was 806 +/- 200 grams, and the mean GA was 25.6 +/- 1.4 weeks. During the first four postnatal weeks, 20.2% of AA/DHA-supplemented infants had thrombocytopenia versus 27.7% of controls (p = 0.29). In infants with thrombocytopenia, fewer AA/DHA-supplemented infants developed severe ROP than non-supplemented controls, 29.4% (5/17) versus 65.4% (17/26) (p = 0.031). Thrombocytopenia and serum levels of AA and DHA correlated with several platelet-related proteins involved in angiogenesis and ROP, such as platelet-derived growth factor subunits A and B and vascular endothelial growth factor. Conclusions AA and DHA supplementation is associated with less severe ROP in thrombocytopenic infants, possibly by modulating platelet activation and function. Impact Postnatal enteral supplementation with arachidonic acid (AA) and docosahexaenoic acid (DHA) to extremely preterm infants reduces the risk of severe retinopathy of prematurity (ROP) in infants with thrombocytopenia. The impact of AA and DHA might be, at least in part, mediated through altered platelet activation. We found that AA and DHA may reduce the risk of severe ROP, possibly by modulating platelet-related proteins involved in angiogenesis. Our findings strongly support that supplementing AA and DHA to extremely preterm infants is crucial and can significantly impact their health.

Abstract Background Cytokines and growth factors (GF) have been implicated in the development of retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD). We hypothesize that even small coordinated changes in inflammatory proteins or GFs may reveal changes in underlying regulating mechanisms that do not induce obvious changes in concentration of individual proteins. We therefore applied correlation network analysis of serum factors to determine early characteristics of these conditions. Methods Concentrations of 17 cytokines and five GFs were measured and analysed in blood samples from cord blood, on day one and during the following month in 72 extremely preterm infants. Spearman’s correlation networks distinguishing BPD and severe ROP patients from non-affected were created. Results Most cytokine concentrations correlated positively with each other and negatively with GFs. Very few individual cytokines differed between patients with and without ROP or BPD. However, networks of differently correlated serum factors were characteristic of the diseases and changed with time. In ROP networks, EPO, G-CSF and IL-8 (cord blood), BDNF and VEGF-A (first month) were prominent. In BPD networks, IL-1β, IGF-1 and IL-17 (day one) were noted. Conclusions Network analysis identifies protein signatures related to ROP or BPD in extremely preterm infants. The identified interactions between serum factors are not evident from the analysis of their individual levels, but may reveal underlying pathophysiological mechanisms in the development of these diseases.

The effects of angiotensin II and angiotensin III on mean arterial pressure, serum aldosterone, and serum corticosterone were studied in normal and sodium depleted, conscious rats. In normal rats, angiotensin III was 76% (p > 0.10) as potent as angiotensin II on aldosterone release but only 31% (p < 0.001) as potent on blood pressure. Following sodium depletion, the pressor responses to both angiotensin II and III were reduced (p < 0.001) (65% and 86% respectively). In addition, the release of aldosterone by both peptides was potentiated by sodium depletion as indicated by an increase in the slope of the dose-response curves. However, in the sodium depleted rats, angiotensin III was only 20% (p < 0.001) as potent as angiotensin II in stimulating aldosterone release. Small changes in serum corticosterone were noted following infusions of both peptides, but unlike the case with aldosterone, sodium depletion did not alter the serum corticosterone responses to the peptides. These invivo experiments taken with invitro studies support the interpretation that angiotensin III could function to control aldosterone release in altered sodium states either as a circulating hormone if present in concentrations far in excess of those of angiotensin II or as a local hormone formed in the adrenal from angiotensin II.

An increasing number of extremely premature infants survive the neonatal period and beyond. Little is known about the maturation of the preterm infant’s metabolome and its relation to the development of morbidities. Using 1H-NMR, we investigated the serum metabolic profile of 87 infants born at a gestational age (GA) <28 weeks [mean GA (SD) 25.4 (1.4) weeks] in samples longitudinally collected from birth to term equivalent age. The infant metabolome was analyzed in relation to GA, postnatal age, nutrition, and preterm morbidities. At postnatal day 1, low GA correlated with high levels of 3-hydroxyisobutyrate, acetate, acetoacetate, acetone, formate, glucose, and valine. Nearly all quantified metabolites displayed postnatal concentration changes. For example, the two phospholipid-related metabolites myo-inositol and ethanolamine displayed a similar decline from birth over the first weeks of life, irrespectively of GA. The proportion of enteral/parenteral energy intake in the first 28 days significantly correlated with mean levels of 52% of the analyzed metabolites. Low enteral energy intake was associated with high serum levels of 3-hydroxyisobutyrate, creatinine, glucose, glycerol, histidine, lactate, leucine, lysine, methionine, ornithine, phenylalanine, proline, threonine, and uridine. There were also significant correlations between high enteral intake and high serum levels of isoleucine and tyrosine. Retinopathy of prematurity (ROP) and bronchopulmonary dysplasia (BPD) outcomes were not significantly associated with metabolite levels in the neonatal period after correcting for multiple testing. In conclusion, the serum metabolome of extremely premature infants changes substantially in the neonatal period, largely driven by the gradual transfer from total parenteral nutrition to full enteral feeding. Further studies are needed to disentangle the intricate relationships between the metabolome, nutritional management, GA, and the development of preterm morbidities.

Sex hormones delivered via plasma transfusions from adult male donors to very preterm infants do not alter the circulating plasma concentrations in the infant, irrespective of gender. Objective To determine if plasma transfusions with male donor plasma to very preterm infants affect circulatory levels of sex steroids. Design and patients Retrospective multicentre cohort study in 19 infants born at gestational age Setting Three neonatal intensive care units in Sweden. Main outcome measures Concentrations of sex steroids and sex hormone-binding globulin (SHBG) in donor plasma and infant plasma measured before and after a plasma transfusion and at 6, 12, 24 and 72 hours. Results The concentrations of progesterone, dehydroepiandrosterone and androstenedione were significantly lower in donor plasma than in infant plasma before the transfusion (median (Q1-Q3) 37.0 (37.0-37.0), 1918 (1325-2408) and 424 (303-534) vs 901 (599-1774), 4119 (2801-14 645) and 842 (443-1684) pg/mL), while oestrone and oestradiol were higher in donor plasma (17.4 (10.4-20.1) and 16.0 (11.7-17.2) vs 3.1 (1.1-10.2) and 0.25 (0.25-0.25) pg/mL). Median testosterone and dihydrotestosterone (DHT) levels were 116-fold and 21-fold higher in donor plasma than pre-transfusion levels in female infants, whereas the corresponding difference was not present in male infants. Plasma sex steroid levels were unchanged after completed transfusion compared with pre-transfusion levels, irrespective of the gender of the receiving infant. The SHBG concentration was significantly higher in donor than in recipient plasma (22.8 (17.1-33.5) vs 10.2 (9.1-12.3) nmol/L) before transfusion but did not change in the infants after the transfusion. Conclusions A single transfusion of adult male plasma to preterm infants had no impact on circulating sex steroid levels.

Background Growth factors important for normal brain development are low in preterm infants. This study investigated the link between growth factors and preterm brain volumes at term. Material/methods Infants born <28 weeks gestational age (GA) were included. Endogenous levels of insulin-like growth factor (IGF)−1, brain-derived growth factor, vascular endothelial growth factor, and platelet-derived growth factor (expressed as area under the curve [AUC] for serum samples from postnatal days 1, 7, 14, and 28) were utilized in a multivariable linear regression model. Brain volumes were determined by magnetic resonance imaging (MRI) at term equivalent age. Results In total, 49 infants (median [range] GA 25.4 [22.9–27.9] weeks) were included following MRI segmentation quality assessment and AUC calculation. IGF-1 levels were independently positively associated with the total brain ( p < 0.001, β = 0.90), white matter ( p = 0.007, β = 0.33), cortical gray matter ( p = 0.002, β = 0.43), deep gray matter ( p = 0.008, β = 0.05), and cerebellar ( p = 0.006, β = 0.08) volume adjusted for GA at birth and postmenstrual age at MRI. No associations were seen for other growth factors. Conclusions Endogenous exposure to IGF-1 during the first 4 weeks of life was associated with total and regional brain volumes at term. Optimizing levels of IGF-1 might improve brain growth in extremely preterm infants. Impact High serum levels of insulin-like growth factor (IGF)-1 during the first month of life were independently associated with increased total brain volume, white matter, gray matter, and cerebellar volume at term equivalent age in extremely preterm infants. IGF-1 is a critical regulator of neurodevelopment and postnatal levels are low in preterm infants. The effects of IGF-1 levels on brain development in extremely preterm infants are not fully understood. Optimizing levels of IGF-1 may benefit early brain growth in extremely preterm infants. The effects of systemically administered IGF-1/IGFBP3 in extremely preterm infants are now being investigated in a randomized controlled trial (Clinicaltrials.gov: NCT03253263).

Introduction: Thrombocytopenia has been identified as an independent risk factor for retinopathy of prematurity (ROP), although underlying mechanisms are unknown. In this study, the association of platelet count and serum platelet-derived factors with ROP was investigated. Methods: Data for 78 infants born at gestational age (GA) <28 weeks were included. Infants were classified as having no/mild ROP or severe ROP. Serum levels of vascular endothelial growth factor A, platelet-derived growth factor BB, and brain-derived neurotrophic factor were measured in serum samples collected from birth until postmenstrual age (PMA) 40 weeks. Platelet counts were obtained from samples taken for clinical indication. Results: Postnatal platelet counts and serum concentrations of the 3 growth factors followed the same postnatal pattern, with lower levels in infants developing severe ROP at PMA 32 and 36 weeks (p < 0.05-0.001). With adjustment for GA, low platelet counts and low serum concentrations of all 3 factors at PMA 32 weeks were significantly associated with severe ROP. Serum concentrations of all 3 factors also strongly correlated with platelet count (p < 0.001). Conclusion: In this article, we show that ROP, platelet counts, and specific pro-angiogenic factors correlate. These data suggest that platelet-released factors might be involved in the regulation of retinal and systemic angiogenesis after extremely preterm birth. Further investigations are needed.

BACKGROUND:Extremely preterm infants are at risk of developing retinopathy of prematurity (ROP) that can cause impaired vision or blindness. Changes in blood lipids have been associated with ROP. This study aimed to monitor longitudinal changes in the serum sphingolipidome of extremely preterm infants and investigate the relationship to development of severe ROP. METHODS:This is a prospective study that included 47 infants born <28 gestational weeks. Serum samples were collected from cord blood and at postnatal days 1, 7, 14, and 28, and at postmenstrual weeks (PMW) 32, 36, and 40. Serum sphingolipids and phosphatidylcholines were extracted and analyzed by LC-MS/MS. Associations between sphingolipid species and ROP were assessed using mixed models for repeated measures. RESULTS:The serum concentration of all investigated lipid classes, including ceramide, mono- di- and trihexosylceramide, sphingomyelin, and phosphatidylcholine displayed distinct temporal patterns between birth and PMW40. There were also substantial changes in the lipid species composition within each class. Among the analyzed sphingolipid species, sphingosine-1-phosphate showed the strongest association with severe ROP, and this association was independent of gestational age at birth and weight standard deviation score change. CONCLUSIONS:The serum phospho- and sphingolipidome undergoes significant remodeling during the first weeks of the preterm infant's life. Low postnatal levels of the signaling lipid sphingosine-1-phosphate are associated with the development of severe ROP.

IMPORTANCE Lack of arachidonic acid (AA) and docosahexaenoic acid (DHA) after extremely preterm birth may contribute to preterm morbidity, including retinopathy of prematurity (ROP). OBJECTIVE To determine whether enteral supplementation with fatty acids from birth to 40 weeks' postmenstrual age reduces ROP in extremely preterm infants. DESIGN, SETTING, AND PARTICIPANTS The Mega Donna Mega trial, a randomized clinical trial, was a multicenter study performed at 3 university hospitals in Sweden from December 15, 2016, to December 15, 2019. The screening pediatric ophthalmologists were masked to patient groupings. A total of 209 infants born at less than 27 weeks' gestation were tested for eligibility, and 206 infants were included. Efficacy analyses were performed on as-randomized groups on the intention-to-treat population and on the per-protocol population using as-treated groups. Statistical analyses were performed from February to April 2020. INTERVENTIONS Infants received either supplementation with an enteral oil providing AA (100mg/kg/d) and DHA (50mg/kg/d) (AA:DHA group) or no supplementation within 3 days after birth until 40 weeks' postmenstrual age. MAIN OUTCOMES AND MEASURES The primary outcomewas severe ROP (stage 3 and/or type 1). The secondary outcomes were AA and DHA serum levels and rates of other complications of preterm birth. RESULTS A total of 101 infants (58 boys [57.4%]; mean [SD] gestational age, 25.5 [1.5] weeks) were included in the AA:DHA group, and 105 infants (59 boys [56.2%]; mean [SD] gestational age, 25.5 [1.4] weeks) were included in the control group. Treatment with AA and DHA reduced severe ROP compared with the standard of care (16 of 101 [15.8%] in the AA:DHA group vs 35 of 105 [33.3%] in the control group; adjusted relative risk, 0.50 [95% CI, 0.28-0.91]; P =.02). The AA:DHA group had significantly higher fractions of AA and DHA in serum phospholipids compared with controls (overall mean difference in AA:DHA group, 0.82 mol% [95% CI, 0.46-1.18 mol%]; P <.001; overall mean difference in control group, 0.13 mol% [95% CI, 0.01-0.24 mol%]; P =.03). There were no significant differences between the AA:DHA group and the control group in the rates of bronchopulmonary dysplasia (48 of 101 [47.5%] vs 48 of 105 [45.7%]) and of any grade of intraventricular hemorrhage (43 of 101 [42.6%] vs 42 of 105 [40.0%]). In the AA:DHA group and control group, respectively, sepsis occurred in 42 of 101 infants (41.6%) and 53 of 105 infants (50.5%), serious adverse events occurred in 26 of 101 infants (25.7%) and 26 of 105 infants (24.8%), and 16 of 101 infants (15.8%) and 13 of 106 infants (12.3%) died. CONCLUSIONS AND RELEVANCE This study found that, compared with standard of care, enteral AA:DHA supplementation lowered the risk of severe ROP by 50% and showed overall higher serum levels of both AA and DHA. Enteral lipid supplementation with AA:DHA is a novel preventive strategy to decrease severe ROP in extremely preterm infants.

Numerous factors are involved in retinopathy of prematurity (ROP) and these differ between preterm infants and fetuses. Sight-threatening pathological retinal neovascularisation may occur during the second phase, due to increased expression of pro-angiogenic factors like vascular endothelial growth factor-A (VEGF-A). Low platelet counts and thrombocytopenia are independent risk factors for ROP. Experimental mice studies have suggested that platelets release stimuli that cause downregulation of retinal VEGF-A and supress neovascularisation (1).

Fetal and early postnatal inflammation have been associated with increased morbidity in extremely preterm infants. This study aimed to demonstrate if postpartum levels of docosahexaenoic acid (DHA) and arachidonic acid (AA) were associated with early inflammation. In a cohort of 90 extremely preterm infants, DHA and AA in cord blood, on the first postnatal day and on postnatal day 7 were examined in relation to early systemic inflammation, defined as elevated C-reactive protein (CRP) and/or interleukin-6 (IL-6) within 72 h from birth, with or without positive blood culture. Median serum level of DHA was 0.5 mol% (95% CI (confidence interval) 0.2–0.9, P = 0.006) lower than the first postnatal day in infants with early systemic inflammation, compared to infants without signs of inflammation, whereas levels of AA were not statistically different between infants with and without signs of inflammation. In cord blood, lower serum levels of both DHA (correlation coefficient −0.40; P = 0.010) and AA (correlation coefficient −0.54; p < 0.001) correlated with higher levels of IL-6. Levels of DHA or AA did not differ between infants with and without histological signs of chorioamnionitis or fetal inflammation. In conclusion, serum levels of DHA at birth were associated with the inflammatory response during the early postnatal period in extremely preterm infants.

BACKGROUND:Preterm birth and its complications are the primary cause of death among children under the age of 5. Among the survivors, morbidity both perinatally and later in life is common. The dawn of novel technical platforms for comprehensive and sensitive analysis of protein profiles in blood has opened up new possibilities to study both health and disease with significant clinical accuracy, here used to study the preterm infant and the physiological changes of the transition from intrauterine to extrauterine life.METHODS:We have performed in-depth analysis of the protein profiles of 14 extremely preterm infants using longitudinal sampling. Medical variables were integrated with extensive profiling of 448 unique protein targets.RESULTS:The preterm infants have a distinct unified protein profile in blood directly at birth regardless of clinical background; however, the pattern changed profoundly postnatally, expressing more diverse profiles only 1 week later and further on up to term-equivalent age. Clusters of proteins depending on temporal trend were identified.CONCLUSION:The protein profiles and the temporal trends here described will contribute to the understanding of the physiological changes in the intrauterine-extrauterine transition, which is essential to adjust early-in-life interventions to prone a normal development in the vulnerable preterm infants.IMPACT:We have performed longitudinal and in-depth analysis of the protein profiles of 14 extremely preterm infants using a novel multiplex protein analysis platform. The preterm infants had a distinct unified protein profile in blood directly at birth regardless of clinical background. The pattern changed dramatically postnatally, expressing more diverse profiles only 1 week later and further on up to term-equivalent age. Certain clusters of proteins were identified depending on their temporal trend, including several liver and immune proteins. The study contributes to the understanding of the physiological changes in the intrauterine-extrauterine transition.

OBJECTIVE:Growth factors in the blood of very preterm infants may reflect growth and contribute to the understanding of early development. We investigated postnatal levels of insulin-like growth factors (IGFs) in infants born very preterm and related them to early growth development. DESIGN:Blood samples were analyzed weekly for IGF-I, IGF-II, IGF binding protein (BP)-1, IGFBP-3, and acid-label subunit (ALS). METHODS:73 children born very preterm (gestational age (GA) <32 weeks) were divided according to their gender-specific birth weight standard deviation score (SDS) into either appropriate for GA (AGA) or small for GA (SGA). Fifty-two (71%) and forty-three (59%) infants completed follow-up with anthropometry at approximately 3 years and at 5 years of age respectively. Thirty-six subjects (49%) had blood sampling for IGF-I and IGFBP-3 measurements up to 3 years of age. RESULTS:IGF-I, IGFBP-3, and ALS levels increased in all groups from week 31 to week 36, with generally lower levels in the SGAs, with a concomitant lower growth velocity. Postnatal ALS was strongly associated with IGF-I and IGFBP-3 in boys, girls and AGA infants. IGF-II was higher in earlier born preterms (GA < 27 weeks) at postmenstrual ages 27.5-29.9 weeks compared with SGAs and late GA (GA ≥ 27 weeks) preterms (p < .0001). IGF-II, in contrast to IGF-I, did not differ between SGAs and AGAs at weeks 31-36. Mean IGFBP-1 was highest in the SGAs compared to AGAs at mean week 28,5 and 31 (p = .001) and IGFBP-1 levels were elevated in relation to IGF-I in the SGAs at that period. At follow-up, the increase in IGF-I between week 31 and 33.5 was a significant positive determinant of height SDS at 3 and 5 years of age in forward multiple regression analysis, independent of target height. CONCLUSION:This is the first study to investigate postnatal ALS levels in preterm infants. In very preterm infants, IGF-II is less affected by size at birth during early postnatal weeks compared with IGF-I. Early elevated IGFBP-1 might protect the SGA infants from an intense metabolic rate. Our results indicate that anabolic and metabolic processes during weeks 31-36 predicts later height.

Numerous factors are involved in retinopathy of prematurity (ROP) and these differ between preterm infants and fetuses. Sight-threatening pathological retinal neovascularisation may occur during the second phase, due to increased expression of pro-angiogenic factors like vascular endothelial growth factor-A (VEGF-A). Low platelet counts and thrombocytopenia are independent risk factors for ROP. Experimental mice studies have suggested that platelets release stimuli that cause downregulation of retinal VEGF-A and supress neovascularisation.1 Low levels of long-chain polyunsaturated fatty acids (LC-PUFAs), like docosahexaenoic acid (DHA) and arachidonic acid (AA), have been associated with ROP.2 LC-PUFAs have enhanced platelet formation from mature megakaryocytes in vitro.3 Low platelet counts and low levels of LC-PUFAs have been associated with ROP, but their inter-relationship has not been evaluated. This was a prospective study of 78 infants born at Sahlgrenska University Hospital, Gothenburg, Sweden, before 28 weeks of gestation in 2013˗2015. We assessed their longitudinal postnatal platelet counts and serum phospholipid-bound fractions of DHA and AA4 in relation to ROP. Blood samples for LC-PUFA analysis and platelet counts were taken from birth until 40 weeks of postmenstrual age (PMA). Thrombocytopenia was any platelet count <100 × 109/L. LC-PUFA levels and platelet counts were used to calculate weekly Pearson correlations for PMAs from 28 to 40 weeks. Two-tailed tests were used and .05 was significant. The analyses were performed using SAS software, version 9.4 (SAS Institute Inc.). Table 1 shows the infants' characteristics and the correlations between DHA, AA and platelet counts. Of these, 28% developed severe ROP requiring treatment at a median PMA of 36.8 (interquartile range 35.4-38.9) weeks and exhibited thrombocytopenia more frequently (82% versus 36%, P < .001) than those with no, or less severe, ROP. Detailed data about their serum fractions of AA and DHA have previously been published.4 Briefly, DHA decreased by 1.14 (95% confidence interval 0.93-1.36, P < .0001) mol% and AA decreased by 7.5 (6.8-8.1, P < .0001) mol% during the first postnatal week. DHA then increased slowly and AA remained low. The associations between DHA, AA and the predicted platelet counts were r = .32 (range 0.23-0.43, P = .0008) and r = 0.23 (0.16-0.34, P = .0045) respectively. They were markedly higher in infants with severe ROP (Table 1), particularly for DHA between 32 and 36 weeks of PMA (range 0.59-0.66), when neovascularisation may occur (Table 1, Figure S1). AA presented an overall weaker association than DHA. We believe that no associations between platelet counts and LC-PUFAs have previously been reported for extremely preterm infants. However, in the 1970s, Freidman et al reported thrombocytopenia in infants with essential fatty acid deficiency and long-time parenteral nutrition.5 We hypothesised that low LC-PUFA would interact negatively with platelet formation. Consequently, platelet derived anti-angiogenic stimuli were decreased which may have contributed to neovascularisation in the second ROP phase. Retinal vascularisation involves a complex interaction and timing of pro-angiogenic or anti-angiogenic factors. In ROP, pathological neovascularisation occurs when retinal expression of VEGF-A is upregulated to meet the demands of the maturing neural retina. An ROP mouse model indicated that platelet alpha-granules released anti-angiogenic stimuli, causing downregulation of retinal VEGF-A transcripts and suppressed neovascularisation during the second ROP phase.1 Platelets are released from mature megakaryocytes in bone marrow through a series of events. Our positive association between LC-PUFAs and platelets was not surprising, as in vitro studies have shown that DHA and AA in culture media improved megakaryocyte migration, maintained platelet membrane structure and affected platelet survival.3 Postnatal LC-PUFA deficiency appears from week one of life and persists during the first few months in extremely preterm infants. Many studies have failed to show the benefits of LC-PUFA supplements in preterm infants. We emphasise the importance of analysing longitudinal serum fraction levels of LC-PUFA, to confirm the effect of supplementation before evaluating any benefits. As previously suggested, PMA-adjusted AA and DHA supplements could prevent morbidities. AA is the predominant LC-PUFA in the retina up to approximately 32 weeks of PMA, when retinal DHA increases and AA decreases. Retinal vascularisation and suppression of vacularisation was higher in phase two ROP in mice fed a DHA, rather than AA, enriched diet. We hypothesise that DHA supplements were especially important in later PMAs, due to a plausible synergistic pathogenesis between platelets and DHA in ROP development. Further studies need to clarify the causality between DHA and AA fractions and platelet counts and address the timing, duration, dosage and optimal ratios of LC-PUFA supplements in extremely preterm infants. This could help to prevent morbidities like severe sight-threatening ROP. None. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Purpose Choline is an essential nutrient for fetal and infant growth and development. Parenteral nutrition used in neonatal care lack free choline but contain small amounts of lipid-bound choline in the form of phosphatidylcholine (PC). Here, we examined the longitudinal development of serum free choline and metabolically related compounds betaine and methionine in extremely preterm infants and how the concentrations were affected by the proportion of parenteral fluids the infants received during the first 28 postnatal days (PNDs). Methods This prospective study included 87 infants born at gestational age (GA) < 28 weeks. Infant serum samples were collected PND 1, 7, 14, and 28, and at postmenstrual age (PMA) 32, 36, and 40 weeks. The serum concentrations of free choline, betaine, and methionine were determined by 1 H NMR spectroscopy. Results The median (25th–75th percentile) serum concentrations of free choline, betaine, and methionine were 33.7 (26.2–41.2), 71.2 (53.2–100.8), and 25.6 (16.4–35.3) µM, respectively, at PND 1. The choline concentration decreased rapidly between PND one and PND seven [18.4 (14.1–26.4) µM], and then increased over the next 90 days, though never reaching PND one levels. There was a negative correlation between a high intake of parenteral fluids and serum-free choline. Conclusion Circulating free choline in extremely preterm infants is negatively affected by the proportion of parenteral fluids administered. Trial registration ClinicalTrials.gov Identifier NCT02760472, April 29, 2016, retrospectively registered.

Objective: Steady state insulin-like growth factor-1 (IGF-1) levels vary significantly during continuous intravenous infusion of recombinant human insulin-like growth factor-1/recombinant human insulin-like growth factor binding protein-3 (rhIGF-1/rhIGFBP-3) in the first weeks of life in extremely preterm infants. We evaluated interleukin-6 (IL-6) and insulin-like growth factor binding protein-1 (IGFBP-1) levels as predictors of low IGF-1 levels. Methods: Nineteen extremely preterm infants were enrolled in a trial, 9 received rhIGF-1/rhIGFBP-3 and 10 received standard neonatal care. Blood samples were analyzed daily for IGF-1, IL-6 and IGFBP-1 during intervention with rhIGP-1/rhIGFBP-3. Results: Thirty seven percent of IGF-1 values during active treatment were < 20 mu g/L. Among treated infants, higher levels of IL-6, one and two days before sampled IGF-1, were associated with IGF-1 < 20 mu g/L, gestational age adjusted OR 1.30 (95% CI 1.03-1.63), p = .026, and 1.57 (95% CI 1.26-1.97), p < .001 respectively. Higher levels of IGFBP-1 one day before sampled IGF-1 was also associated with IGF-1 < 20 mu g/L, gestational age adjusted OR 1.74 (95% CI 1.19-2.53), p = .004. Conclusion: In preterm infants receiving continuous infusion of rhIGF-1/rhIGFBP-3, higher levels of IL-6 and IGFBP-1 preceded lower levels of circulating IGF-1. These findings demonstrate a need to further evaluate if inflammation and/or infection suppress serum IGF-1 levels.

Context: Little is known about the individual response of glucose-regulating factors to administration of exogenous insulin infusion in extremely preterm infants. Objective: To evaluate longitudinal serum concentrations of insulin, C-peptide, and plasma glucose levels in a high-frequency sampling regimen in extremely preterm infants treated with insulin because of hyperglycemia. Design: Prospective longitudinal cohort study. Setting: Two university hospitals in Sweden between December 2015 and September 2016. Patients and Intervention: Serum samples were obtained from nine extremely preterm infants, gestational age between 22 (+3) and 26 (+5) weeks (+ days), with hyperglycemia (plasmaglucose >10 mmol/L) at the start of insulin infusion, at 12, 24, and every 24 hours thereafter during ongoing infusion, and 12, 24, and 72 hours after the end of insulin infusion. Main outcome measures: Longitudinal serum concentrations of insulin and C-peptide and plasma glucose levels. Results: During insulin infusion, the serum C-peptide concentrations decreased compared with at start of infusion (P = 0.036), and then increased after ending the infusion. Individual insulin sensitivity based on the nonfasting plasma glucose/insulin ratio at the start of insulin infusion correlated with the initial decrease in serum Delta C-peptide([after 12h]) (P = 0.007) and the degree of lasting decrease in serum Delta C-peptide([after end of infusion]) (P = 0.015). Conclusion: Exogenous insulin infusion suppressed the C-peptide concentration to individually different degrees. In addition, the effect of insulin infusion on beta cells may be linked to individual insulin sensitivity, where a low insulin sensitivity resulted in a more pronounced decrease in C-peptide during insulin infusion.

AbstractBackgroundInfants born prematurely are at risk of a deficiency in ω‐6 and ω‐3 long‐chain polyunsaturated fatty acids (LC‐PUFAs) arachidonic acid (AA) and docosahexaenoic acid (DHA). We investigated how fatty acids from breast milk and parenteral lipid emulsions shape serum LC‐PUFA profiles in extremely preterm infants during early perinatal life.MethodsNinety infants born < 28 weeks gestational age were randomized to receive parenteral lipids with or without the ω‐3 LC‐PUFAs eicosapentaenoic acid (EPA) and DHA (SMOFlipid: Fresenius Kabi, Uppsala, Sweden, or Clinoleic: Baxter Medical AB, Kista, Sweden, respectively). The fatty acid composition of infant serum phospholipids was determined from birth to postmenstrual age 40 weeks, and in mother's milk total lipids on postnatal day 7. Enteral and parenteral intake of LC‐PUFAs was correlated with levels in infant serum.ResultsInfants administered parenteral ω‐3 LC‐PUFAs received 4.4 and 19.3 times more DHA and EPA, respectively, over the first 2 weeks of life. Parenteral EPA but not DHA correlated with levels in infant serum. We found linear relationships between dietary EPA and DHA and infant serum levels in the Clinoleic (Baxter Medical AB) group. The volume of administered SMOFlipid (Fresenius Kabi) was inversely correlated with serum AA, whereas Clinoleic (Baxter Medical AB) inversely correlated with serum EPA and DHA.ConclusionsThere appears to be no or low correlation between the amount of DHA administered parenterally and levels measured in serum. Whether this observation reflects serum phospholipid fraction only or truly represents the amount of accreted DHA needs to be investigated. None of the parenteral lipid emulsions satisfactorily maintained high levels of both ω‐6 and ω‐3 LC‐PUFAs in infant serum.