High protein intake on later outcomes in preterm children: a systematic review and meta-analysis.

BACKGROUND: Appropriate protein intake is crucial for growth and development in children born preterm. We assessed the effects of high (HP) versus low protein (LP) intake on neurodevelopment, growth, and biochemical anomalies in these children. METHODS: Randomised and quasi-randomised trials providing protein to children born preterm (<37 completed weeks of gestation) were searched following PRISMA guideline in three databases and four registers (PROSPERO registration CRD42022325659). Random-effects model was used for assessing the effects of HP (≥3.5 g/kg/d) vs. LP (<3.5 g/kg/d). RESULTS: Data from forty-four studies (n = 5338) showed HP might slightly reduce the chance of survival without neurodisability at ≥12 months (four studies, 1109 children, relative risk [RR] 0.95 [95% CI 0.90, 1.01]; P = 0.13; low certainty evidence) and might increase risk of cognitive impairment at toddler age (two studies; 436 children; RR 1.36 [0.89, 2.09]; P = 0.16; low certainty evidence). At discharge or 36 weeks, HP intake might result in higher weight and greater head circumference z-scores. HP intake probably increased the risk of hypophosphatemia, hypercalcemia, refeeding syndrome and high blood urea, but reduced risk of hyperglycaemia. CONCLUSIONS: HP intake for children born preterm may be harmful for neonatal metabolism and later neurodisability and has few short-term benefits for growth. IMPACT STATEMENT: Planned high protein intake after birth for infants born preterm might be harmful for survival, neurodisability and metabolism during infancy and did not improve growth after the neonatal period. Protein intake ≥3.5 g/kg/d should not be recommended for children born preterm.

Postnatal growth and neurodevelopment at 2 years' corrected age in extremely low birthweight infants.

BACKGROUND: Faltering postnatal growth in preterm babies is associated with adverse neurodevelopment. However, which growth reference is most helpful for predicting neurodevelopment is unknown. We examined associations between faltering growth and developmental delay in extremely low birthweight (ELBW) infants. METHODS: We categorized faltering growth (z-score decrease ≥0.8 for weight/length, >1 for head circumference) between birth, 4 weeks, 36 weeks' postmenstrual age and 2 years' corrected age using fetal (Fenton, UK-WHO and Olsen) and healthy preterm (INTERGROWTH-21st) references. Associations between faltering growth and developmental delay were examined using binary logistic regression and area under the receiver operating curve (AUC). RESULTS: In 327 infants, Olsen charts identified the highest prevalence of faltering growth (weight 37%, length 63%, head 45%). Agreement in classification was higher amongst fetal references (kappa coefficient, ĸ = 0.46-0.94) than between INTERGROWTH-21st and fetal references (ĸ = 0.10-0.81). Faltering growth in all measures between 4-36 weeks (odds ratio, OR 2.0-4.7) compared with other time intervals (OR 1.7-2.7) were more strongly associated with developmental delay, particularly motor delay (OR 2.0-4.7). All growth references were poorly predictive of developmental delay at 2 years (AUC ≤ 0.62). CONCLUSIONS: Faltering postnatal growth in ELBW infants is associated with, but is poorly predictive of, developmental delay at 2 years. IMPACT: In babies born preterm, different growth references result in wide variation in categorization of faltering postnatal growth. Faltering growth in weight, length, and head circumference from 4 weeks to 36 weeks' postmenstrual age are associated with developmental delay at 2 years' corrected age, particularly motor delay. However, postnatal growth is a poor predictor of later developmental delay in extremely low birthweight infants irrespective of the growth reference used.

Nutrition guidelines for preterm infants: A systematic review.

BACKGROUND: There is no consensus on optimal nutrition for preterm infants, leading to substantial practice variation. We aimed to assess the quality of nutrition guidelines for preterm infants, the consistency of recommendations, and the gaps in recommendations. METHODS: We searched databases and websites for nutrition guidelines for preterm infants before first hospital discharge, which were endorsed, prepared, or authorized by a regional, national, or international body, written in English, and published between 2012 and 2023. Two reviewers independently screened articles and extracted the recommendations. Four reviewers appraised the included guidelines using Appraisal of Guidelines, Research, and Evaluation II. RESULTS: A total of 7051 were identified, with 27 guidelines included, 26% of which were high in quality. Most guidelines lacked stakeholder involvement and rigor of development. We found considerable variation in recommendations, many of which lacked details on certainty of evidence and strength of recommendation. Recommendations for type of feed and breastmilk fortification were consistent among high-quality guidelines, but recommendations varied for intakes of almost all nutrients and monitoring of nutrition adequacy. Different guidelines gave different certainty of evidence for the same recommendations. Most gaps in recommendations were due to very low certainty of evidence. CONCLUSION: Future development of nutrition guidelines for preterm infants should follow the standard guideline development method and ensure the rigorous process, including stakeholders' involvement, to improve the reporting of strength of recommendation, certainty of evidence, and gaps in recommendation. Evidence is needed to support recommendations about macro and micronutrient intakes, breastmilk fortification, and markers on adequacy of intake of different nutrients.

Evaluation of Immune Infiltrates in Ovarian Endometriosis and Endometriosis-Associated Ovarian Cancer: Relationship with Histological and Clinical Features.

BACKGROUND: the association between ovarian endometriosis (OE) and endometriosis-associated ovarian cancer (EAOC) is extensively documented, and misfunction of the immune system might be involved. The primary objective of this study was to identify and compare the spatial distribution of tumour-infiltrating lymphocytes (TILs) and tumour-associated macrophages (TAMs) in OE and EAOC. Secondary objectives included the analysis of the relationship between immunosuppressive populations and T-cell exhaustion markers in both groups. METHODS: TILs (CD3, CD4, and CD8) and macrophages (CD163) were assessed by immunochemistry. Exhaustion markers (PD-1, TIM3, CD39, and FOXP3) and their relationship with tumour-associated macrophages (CD163) were assessed by immunofluorescence on paraffin-embedded samples from n = 43 OE and n = 54 EAOC patients. RESULTS: we observed a predominantly intraepithelial CD3+ distribution in OE but both an intraepithelial and stromal pattern in EAOC (p < 0.001). TILs were more abundant in OE (p < 0.001), but higher TILs significantly correlated with a longer overall survival and disease-free survival in EAOC (p < 0.05). CD39 and FOXP3 significantly correlated with each other and CD163 (p < 0.05) at the epithelial level in moderate/intense CD4 EAOC, whereas in moderate/intense CD8+, PD-1+ and TIM3+ significantly correlated (p = 0.009). Finally, T-cell exhaustion markers FOXP3-CD39 were decreased and PD-1-TIM3 were significantly increased in EAOC (p < 0.05). CONCLUSIONS: the dysregulation of TILs, TAMs, and T-cell exhaustion might play a role in the malignization of OE to EAOC.

Hypophosphataemia definitions, incidence and associated outcomes in paediatric intensive care: A retrospective cohort study in post-cardiac surgical patients <2 years of age.

AIM: Hypophosphataemia has been linked to higher morbidity and mortality in intensive care but there is inconsistency in the definition of hypophosphataemia for infants and children. We aimed to determine the incidence of hypophosphataemia in a group of at-risk children in paediatric intensive care unit (PICU) and associations with patient characteristics and clinical outcomes using three different hypophosphataemia thresholds. METHODS: Retrospective cohort study of 205 post-cardiac surgical patients <2 years of age admitted to Starship Child Health PICU, Auckland, New Zealand. Patient demographics and routine daily biochemistry for 14 days after PICU admission were collected. Rates of sepsis, mortality and length of mechanical ventilation were compared between groups with different serum phosphate concentrations. RESULTS: Out of 205 children, 6 (3%), 50 (24%) and 159 (78%) had hypophosphataemia at thresholds of <0.7, <1.0 and <1.4 mmol/L, respectively. There were no differences in gestational age at birth, sex, ethnicity or mortality in those with and without hypophosphataemia at any threshold. Children with a serum phosphate <1.4 mmol/L had more mean (SD) total hours of mechanical ventilation (85.2 (79.6) vs. 54.9 (36.2) h, P = 0.02) and those with mean serum phosphate <1.0 mmol/L had more mean hours of mechanical ventilation (119.4 (102.8) vs. 65.2 (54.8) h, P < 0.0001), episodes of sepsis (14% vs. 5%, P = 0.03) and longer length of stay (6.4 (4.8-20.7) vs. 4.9 (3.9-6.8) days, P = 0.02). CONCLUSIONS: Hypophosphataemia is common in this PICU cohort and serum phosphate <1.0 mmol/L is associated with increased morbidity and length of stay.

New Roles for Old Friends: Involvement of the Innate Immune System in Tumor Progression.

The association between the immune system and tumor progression has attracted much interest in the research community in recent years [...].

Neutrophil Extracellular Traps and Cancer: Trapping Our Attention with Their Involvement in Ovarian Cancer.

Neutrophils, the most abundant circulating leukocytes, play a well-known role in defense against pathogens through phagocytosis and degranulation. However, a new mechanism involving the release of neutrophil extracellular traps (NETs) composed of DNA, histones, calprotectin, myeloperoxidase, and elastase, among others, has been described. The so-called NETosis process can occur through three different mechanisms: suicidal, vital, and mitochondrial NETosis. Apart from their role in immune defense, neutrophils and NETs have been involved in physiopathological conditions, highlighting immunothrombosis and cancer. Notably, neutrophils can either promote or inhibit tumor growth in the tumor microenvironment depending on cytokine signaling and epigenetic modifications. Several neutrophils' pro-tumor strategies involving NETs have been documented, including pre-metastatic niche formation, increased survival, inhibition of the immune response, and resistance to oncologic therapies. In this review, we focus on ovarian cancer (OC), which remains the second most incidental but the most lethal gynecologic malignancy, partly due to the presence of metastasis, often omental, at diagnosis and the resistance to treatment. We deepen the state-of-the-art on the participation of NETs in OC metastasis establishment and progression and their involvement in resistance to chemo-, immuno-, and radiotherapies. Finally, we review the current literature on NETs in OC as diagnostic and/or prognostic markers, and their contribution to disease progression at early and advanced stages. The panoramic view provided in this article might pave the way for enhanced diagnostic and therapeutic strategies to improve the prognosis of cancer patients and, specifically, OC patients.

Special Issue "miRNAs in the Era of Personalized Medicine: From Biomarkers to Therapeutics 2.0".

Personalized medicine has become a new paradigm in the management of a variety of diseases [...].

Increased levels of NETosis biomarkers in high-grade serous ovarian cancer patients' biofluids: Potential role in disease diagnosis and management.

Introduction: High-grade serous ovarian cancer (HGSOC) is the second most frequent gynecological malignancy but the most lethal, partially due to the spread of the disease through the peritoneal cavity. Recent evidence has shown that, apart from their role in immune defense through phagocytosis and degranulation, neutrophils are able to participate in cancer progression through the release of neutrophil extracellular traps (NETs) in a process called NETosis. NETs are composed of DNA, histones, calprotectin, myeloperoxidase (MPO) and elastase and the NETosis process has been proposed as a pre-requisite for the establishment of omental metastases in early stages of HGSOC. Nevertheless, its role in advanced stages remains to be elucidated. Therefore, our principal aim is to characterize a NETosis biomarker profile in biofluids from patients with advanced HGSOC and control women. Methods: Specifically, five biomarkers of NETosis (cell-free DNA (cfDNA), nucleosomes, citrullinated histone 3 (citH3), calprotectin and MPO) were quantified in plasma and peritoneal fluid (PF) samples from patients (n=45) and control women (n=40). Results: Our results showed that HGSOC patients presented a higher concentration of cfDNA, citH3 and calprotectin in plasma and of all five NETosis biomarkers in PF than control women. Moreover, these biomarkers showed a strong ability to differentiate the two clinical groups. Interestingly, neoadjuvant treatment (NT) seemed to reduce NETosis biomarkers mainly systemically (plasma) compared to the tumor environment (PF). Discussion: In conclusion, NETosis biomarkers are present in the tumor environment of patients with advanced HGSOC, which might contribute to the progression of the disease. Besides, plasma cfDNA and calprotectin could represent minimally invasive surrogate biomarkers for HGSOC. Finally, NT modifies NETosis biomarkers levels mainly at the systemic level.

Early Amino Acids in Extremely Preterm Infants and Neurodisability at 2 Years.

BACKGROUND: Whether higher parenteral amino acid intake improves outcomes in infants with extremely low birth weight is unclear. METHODS: In this multicenter, parallel-group, double-blind, randomized, placebo-controlled trial, we assigned infants with birth weights of less than 1000 g at 8 neonatal intensive care units to receive amino acids at a dose of 1 g per day (intervention group) or placebo in addition to usual nutrition for the first 5 days after birth. The primary outcome was survival free from neurodisability as assessed with the Bayley Scales of Infant and Toddler Development and neurologic examination at 2 years, corrected for gestational age at birth. Secondary outcomes were the components of the primary outcome as well as the presence or absence of neonatal disorders, the rate of growth, and nutritional intake. RESULTS: We enrolled 434 infants (217 per group) in this trial. Survival free from neurodisability was observed in 97 of 203 children (47.8%) in the intervention group and in 102 of 205 (49.8%) in the placebo group (adjusted relative risk, 0.95; 95% confidence interval [CI], 0.79 to 1.14; P = 0.56). Death before the age of 2 years occurred in 39 of 217 children (18.0%) in the intervention group and 42 of 217 (19.4%) in the placebo group (adjusted relative risk, 0.93; 95% CI, 0.63 to 1.36); neurodisability occurred in 67 of 164 children (40.9%) in the intervention group and 61 of 163 (37.4%) in the placebo group (adjusted relative risk, 1.16; 95% CI, 0.90 to 1.50). Neurodisability was moderate to severe in 27 children (16.5%) in the intervention group and 14 (8.6%) in the placebo group (adjusted relative risk, 1.95; 95% CI, 1.09 to 3.48). More children in the intervention group than in the placebo group had patent ductus arteriosus (adjusted relative risk, 1.65; 95% CI, 1.11 to 2.46). In a post hoc analysis, refeeding syndrome occurred in 42 of 172 children in the intervention group and 26 of 166 in the placebo group (adjusted relative risk, 1.64; 95% CI, 1.09 to 2.47). Eight serious adverse events occurred. CONCLUSIONS: In infants with extremely low birth weight, extra parenteral amino acids at a dose of 1 g per day for 5 days after birth did not increase the number who survived free from neurodisability at 2 years. (Funded by the New Zealand Health Research Council and others; ProVIDe Australian New Zealand Clinical Trials Registry number, ACTRN12612001084875.).

Effect of urolithins A and B on ectopic endometrial growth in a murine model of endometriosis.

Endometriosis is an often painful disease in reproductive-aged women, in which endometrial-like tissue grows outside the uterine cavity. Since the limited current therapeutic alternatives fail in alleviating the symptoms and based on our previous research in in vitro models using the same compounds as the ones used in the present study, we aimed to evaluate the effects of urolithins A (UA) and B (UB) on the growth and survival of endometriotic-like lesions in a murine model of endometriosis. Female BALB/C mice were surgically induced with endometriosis and treated with 2.5 mg kg-1 day-1 intraperitoneal UA or UB. The mice were monitored daily and weighed and the estrous stage was determined. After 28 days of treatment, lesions were counted, measured, excised, and fixed. Both urolithins proved not to affect the estrous cycle or body weight of the mice. UA completely prevented endometriotic-like lesions, while UB diminished the implant volume (p < 0.05). Treatment also reduced epithelial and stromal cell proliferation within the implants (p < 0.001 and p < 0.01, respectively) and apoptosis was enhanced (p < 0.05 and p < 0.01, respectively). These results are promising and reveal that urolithins A and B, separately, have a beneficial effect on the overall endometriotic growth without affecting the body weight or estrous cycle.

Variation in Neonatal Nutrition Practice and Implications: A Survey of Australia and New Zealand Neonatal Units.

Background: Significant global variation exists in neonatal nutrition practice, including in assigned milk composition values, donor milk usage, fortification regimens, probiotic choice and in methods used to calculate and report nutrition and growth outcomes, making it difficult to synthesize data to inform evidence-based, standardized nutritional care that has potential to improve neonatal outcomes. The Australasian Neonatal Dietitians' Network (ANDiN) conducted a survey to determine the degree to which neonatal nutritional care varies across Australia and New Zealand (A&NZ) and to highlight potential implications. Materials and Methods: A two-part electronic neonatal nutritional survey was emailed to each ANDiN member (n = 50). Part-One was designed to examine individual dietetic practice; Part-Two examined site-specific nutrition policies and practices. Descriptive statistics were used to examine the distribution of responses. Results: Survey response rate: 88%. Across 24 NICU sites, maximum fluid targets varied (150-180 mL.kg.d-1); macronutrient composition estimates for mothers' own(MOM) and donor (DM) milk varied (Energy (kcal.dL-1) MOM: 65-72; DM 69-72: Protein (g.dL-1): MOM: 1.0-1.5; DM: 0.8-1.3); pasteurized DM or unpasteurized peer-to-peer DM was not available in all units; milk fortification commenced at different rates and volumes; a range of energy values (kcal.g-1) for protein (3.8-4.0), fat (9.0-10.0), and carbohydrate (3.8-4.0) were used to calculate parenteral and enteral intakes; probiotic choice differed; and at least seven different preterm growth charts were employed to monitor growth. Discussion: Our survey identifies variation in preterm nutrition practice across A&NZ of sufficient magnitude to impact nutrition interventions and neonatal outcomes. This presents an opportunity to use the unique skillset of neonatal dietitians to standardize practice, reduce uncertainty of neonatal care and improve the quality of neonatal research.

miRNAs in the Era of Personalized Medicine: From Biomarkers to Therapeutics.

In recent years, interest in personalized medicine has considerably increased [...].

The ellagic acid metabolites urolithin A and B differentially affect growth, adhesion, motility, and invasion of endometriotic cells in vitro.

STUDY QUESTION: What are the effects of plant-derived antioxidant compounds urolithin A (UA) and B (UB) on the growth and pathogenetic properties of an in vitro endometriosis model? SUMMARY ANSWER: Both urolithins showed inhibitory effects on cell behavior related to the development of endometriosis by differentially affecting growth, adhesion, motility, and invasion of endometriotic cells in vitro. WHAT IS KNOWN ALREADY: Endometriosis is one of the most common benign gynecological diseases in women of reproductive age and is defined by the presence of endometrial tissue outside the uterine cavity. As current pharmacological therapies are associated with side effects interfering with fertility, we aimed at finding alternative therapeutics using natural compounds that can be administered for prolonged periods with a favorable side effects profile. STUDY DESIGN, SIZE, DURATION: In vitro cultures of primary endometriotic stromal cells from 6 patients subjected to laparoscopy for benign pathologies with histologically confirmed endometriosis; and immortalized endometrial stromal (St-T1b) and endometriotic epithelial cells (12Z) were utilized to assess the effects of UA and UB on endometriotic cell properties. Results were validated in three-dimensional (3D) in vitro co-culture spheroids of 12Z and primary endometriotic stroma cells of one patient, and organoids from 3 independent donors with endometriosis. PARTICIPANTS/MATERIALS, SETTING, METHODS: The effects on cell growth were measured by non-radioactive colorimetric assay to measure cellular metabolic activity as an indicator of cell viability (MTT assay) and flow cytometric cell cycle assay on primary cultures, St-T1b, and 12Z. Apoptosis analyses, the impact on in vitro adhesion, migration, and invasion were evaluated in the cell lines. Moreover, Real-Time Quantitative Reverse Transcription polymerase chain reaction (RT-qPCR) assays were performed on primary cultures, St- T1b and 12Z to evaluate a plausible mechanistic contribution by factors related to proteolysis (matrix metalloproteinase 2, 3 and 9 -MMP2, MMP3, MMP9-, and tissue inhibitor of metalloproteinases -TIMP-1-), cytoskeletal regulators (Ras-related C3 botulinum toxin substrate 1 -RAC1-, Rho-associated coiled-coil containing protein kinase 2 -ROCK2-), and cell adhesion molecules (Syndecan 1 -SDC1-, Integrin alpha V-ITGAV-). Finally, the urolithins effects were evaluated on spheroids and organoids by formation, viability, and drug screen assays. MAIN RESULTS AND THE ROLE OF CHANCE: 40 µM UA and 20 µM UB produced a significant decrease in cell proliferation in the primary endometriotic cell cultures (P < 0.001 and P < 0.01, respectively) and in the St-T1b cell line (P < 0.001 and P < 0.05, respectively). In St-T1b, UA exhibited a mean half-maximum inhibitory concentration (IC50) of 39.88 µM, while UB exhibited a mean IC50 of 79.92 µM. Both 40 µM UA and 20 µM UB produced an increase in cells in the S phase of the cell cycle (P < 0.01 and P < 0.05, respectively). The same concentration of UA also increased the percentage of apoptotic ST-t1b cells (P < 0.05), while both urolithins decreased cell migration after 24 h (P < 0.001 both). Only the addition of 5 µM UB decreased the number of St-T1b adherent cells. TIMP-1 expression was upregulated in response to treating the cells with 40 µM UA (P < 0.05). Regarding the 12Z endometriotic cell line, only 40 µM UA decreased proliferation (P < 0.01); while both 40 µM UA and 20 µM UB produced an increase in cells in the G2/M phase (P < 0.05 and P < 0.01, respectively). In this cell line, UA exhibited a mean IC50 of 40.46 µM, while UB exhibited a mean IC50 of 54.79 µM. UB decreased cell migration (P < 0.05), and decreased the number of adherent cells (P < 0.05). Both 40 µM UA and 20 µM UB significantly decreased the cellular invasion of these cells; and several genes were altered when treating the cells with 40 µM UA and 10 µM UB. The expression of MMP2 was downregulated by UA (P < 0.001), and expression of MMP3 (UA P < 0.001 and UB P < 0.05) and MMP9 (P < 0.05, both) were downregulated by both urolithins. Moreover, UA significantly downregulated ROCK2 (P < 0.05), whereas UB treatment was associated with RAC1 downregulation (P < 0.05). Finally, the matrix adhesion receptors and signaling (co)receptors SDC1 and ITGAV were downregulated upon treatment with either UA or UB (P < 0.01 and P < 0.05, respectively in both cases). Regarding the effects of urolithins on 3D models, we have seen that they significantly decrease the viability of endometriosis spheroids (80 µM UA and UB: P < 0.05 both) as well as affecting their area (40 µM UA: P < 0.05, and 80 µM UA: P < 0.01) and integrity (40 µM UA and UB: P < 0.05, 80 µM UA and UB: P < 0.01). On the other hand, UA and UB significantly inhibited organoid development/outgrowth (40 and 80 µM UA: P < 0.0001 both; 40 µM UB: P < ns-0.05-0.001, and 80 µM UB: P < 0.01-0.001-0.001), and all organoid lines show urolithins sensitivity resulting in decreasing viability (UA exhibited a mean IC50 of 33.93 µM, while UB exhibited a mean IC50 of 52.60 µM). LARGE-SCALE DATA: N/A. LIMITATIONS, REASONS FOR CAUTION: This study was performed on in vitro endometriosis models. WIDER IMPLICATIONS OF THE FINDINGS: These in vitro results provide new insights into the pathogenetic pathways affected by these compounds and mark their use as a potential new therapeutic strategy for the treatment of endometriosis. STUDY FUNDING/COMPETING INTEREST(S): This study was funded EU MSCA-RISE-2015 project MOMENDO (691058). The authors have no conflicts of interest to declare.

Strategies in Neonatal Care to Promote Growth and Neurodevelopment of the Preterm Infant.

Recommendations for nutrition of very preterm and very low birth weight infants have developed over time with our understanding of the requirements of preterm babies and the awareness of widespread poor postnatal growth. In general, the trend has been towards enhancing nutrition, but more recent recommendations have begun to raise questions with respect to the potential for high and early nutritional intakes, particularly of protein, to carry risks such as refeeding syndrome. However, large gaps in our knowledge remain for both macro- and micronutrient requirements to support optimal growth and how nutrition and growth relate to important long-term outcomes. Closing these knowledge gaps has been hampered by inconsistent reporting of nutrition intakes and growth parameters, small trials with short-term outcomes and the use of a variety of different methods of monitoring growth. The challenge now is for future research to address these issues through consensus building around the important questions that need to be answered, how to report data from neonatal nutritional trials and whether large trials answering important questions can take place through development of consortia that undertake similar trials in multiple jurisdictions with agreements to share data.

Neonatal Refeeding Syndrome and Clinical Outcome in Extremely Low-Birth-Weight Babies: Secondary Cohort Analysis From the ProVIDe Trial.

BACKGROUND: Refeeding syndrome (RS) following preterm birth has been linked to high intravenous (IV) protein intake in the presence of low electrolyte supply. In extremely low-birth-weight (ELBW) babies, we aimed to determine the incidence of RS and associations with birth characteristics and clinical outcomes. METHOD: Prospective cohort study of ELBW ProVIDe Trial participants in 6 New Zealand neonatal intensive care units. RS was defined as serum phosphate < 1.4 mmol.L-1 and total calcium > 2.8 mmol.L-1 . Relationships between RS and other factors were explored using 2-sample tests and logistic regression adjusted for sex, gestation, and birth-weight z-score. RESULTS: Of 338 babies (mean [SD] birth-weight, 780 (134) g, gestational age, 25.9 [1.7] weeks), 68 (20%) had RS. Mortality was greater in babies with RS (32% vs 11%; P < .0001). More small- than appropriate-for-gestational-age babies developed RS (22% vs 8%; P = .001). Growth from birth to 36 weeks' corrected age was not different between babies who did and did not have RS. In logistic regression, the odds of RS decreased by 70% for each 1 mmol per kg-1 .d-1 IV phosphate intake (odds ratio [OR], 0.3; CI, 0.1-0.6; P = .002) and increased by 80% for each 1 g.kg-1 .d-1 IV protein intake (OR, 1.8; CI, 1.3-2.7; P = .002). CONCLUSIONS: Neonatal RS is common in this cohort of ELBW babies and is associated with increased morbidity and mortality. Optimizing phosphate and calcium intakes in IV nutrition solutions may reduce RS and its consequences.