Elisabeth Stoltz Sjöström

Nutrient intakes independently affect growth in extremely preterm infants: results from a population-based study

To explore associations between energy and macronutrient intakes and early growth in extremely low gestational age (ELGA) infants.

WINROP Identifies Severe Retinopathy of Prematurity at an Early Stage in a Nation-Based Cohort of Extremely Preterm Infants

Objective To evaluate the ability of a postnatal weight-gain algorithm (WINROP) to identify sight-threatening retinopathy of prematurity (ROP type 1) in a nation-based extremely preterm infant cohort. Methods This study enrolled all 707 live-born extremely preterm (gestational age [GA] <27 weeks) infants, born 2004–2007 in Sweden; the Extremely preterm Infants in Sweden Study (EXPRESS). WINROP analysis was performed retrospectively in 407 of the infants using weekly weight gain to assess the preterm infant’s risk of developing ROP type 1 requiring treatment. GA, birthweight (BW), and weekly postnatal weight measurements were entered into WINROP. WINROP signals with an alarm to indicate if the preterm infant is at risk for ROP type 1. Results In this extremely preterm population, WINROP correctly identified 96% (45/47) of the infants who required treatment for ROP type 1. The median time from alarm to treatment was 9 weeks (range, 4–20 weeks). Conclusions WINROP, an online surveillance system using weekly weight gain, identified extremely preterm infants at risk for ROP type 1 requiring treatment at an early stage and with high sensitivity in a Swedish nation-based cohort.

Low energy intake during the first 4 weeks of life increases the risk for severe retinopathy of prematurity in extremely preterm infants.

Objectives Poor weight gain during the first weeks of life in preterm infants is closely associated with the risk of developing the retinopathy of prematurity (ROP) and insufficient nutrition might be an important contributing factor. This study aimed to evaluate the effect of energy and macronutrient intakes during the first 4 weeks of life on the risk for severe ROP (stages 3–5). Study design A population-based study including all Swedish extremely preterm infants born before 27 gestational weeks during a 3-year period. Each infant was classified according to the maximum stage of ROP in either eye as assessed prospectively until full retinal vascularisation. The detailed daily data of actual intakes of enteral and parenteral nutrition and growth data were obtained from hospital records. Results Of the included 498 infants, 172 (34.5%) had severe ROP and 96 (19.3%) were treated. Energy and macronutrient intakes were less than recommended and the infants showed severe postnatal growth failure. Higher intakes of energy, fat and carbohydrates, but not protein, were significantly associated with a lower risk of severe ROP. Adjusting for morbidity, an increased energy intake of 10 kcal/kg/day was associated with a 24% decrease in severe ROP. Conclusions We showed that low energy intake during the first 4 weeks of life was an independent risk factor for severe ROP. This implies that the provision of adequate energy from parenteral and enteral sources during the first 4 weeks of life may be an effective method for reducing the risk of severe ROP in extremely preterm infants.

Intake and macronutrient content of human milk given to extremely preterm infants

Background: Human milk (HM) is the preferred basis of nutrition for infants, including those born prematurely. Information on HM macronutrient content is necessary to optimize nutritional support of preterm infants. Objectives: This study aimed to describe the types and amounts of enteral feeds given to Swedish extremely preterm infants during hospitalization and to investigate the energy and macronutrient contents in HM given to these infants. Methods: A population-based study of Swedish extremely preterm infants (n = 586) born before 27 gestational weeks was conducted. Data on ingested volumes of different milk during hospitalization and analyses of macronutrient content in HM samples were obtained from hospital records. Nutritional content of HM was determined by mid-infrared spectrophotometry analysis. Results: During the first 4 weeks of life, 99% of the infants were exclusively fed HM, and at 4 weeks of life, 70% of the infants received only mother’s own milk (MOM). Nutritional content in 821 MOM samples was analyzed. Protein content in MOM decreased significantly from 2.2 to 1.2 g/100 mL during the first 112 postpartum days, whereas fat and energy content were highly variable within and between MOM samples. In addition, 354 samples of donor milk were analyzed. Content of protein, fat, and energy in pooled donor milk (n = 129) was lower compared to single donor milk. Conclusion: Swedish extremely preterm infants receive MOM to a large extent during hospitalization. Protein, carbohydrates, and energy in MOM changed significantly with time. Weekly analyses of MOM during the first month of lactation would allow more individualized nutritional support for these vulnerable infants.

Perioperative nutrition in extremely preterm infants undergoing surgical treatment for patent ductus arteriosus is suboptimal.

To evaluate perioperative nutrition in extremely preterm infants undergoing surgery for patent ductus arteriosus (PDA).

Intakes of Micronutrients Are Associated With Early Growth in Extremely Preterm Infants

Objectives: The aim of the study was to describe micronutrient intakes and explore possible correlations to growth during the first 70 days of life in extremely preterm infants. Methods: Retrospective population-based study including extremely preterm infants (<27 weeks) born in Sweden during 2004–2007. Detailed nutritional and growth data were derived from hospital records. Results: Included infants (n = 531) had a mean gestational age of 25 weeks and 2 days and a mean birth weight of 765 g. Estimated and adjusted intakes of calcium, phosphorus magnesium, zinc, copper, selenium, vitamin D, and folate were lower than estimated requirements, whereas intakes of iron, vitamin K, and several water-soluble vitamins were higher than estimated requirements. High iron intakes were explained by blood transfusions. During the first 70 days of life, taking macronutrient intakes and severity of illness into account, folate intakes were positively associated with weight (P = 0.001) and length gain (P = 0.003) and iron intake was negatively associated with length gain (P = 0.006). Conclusions: Intakes of several micronutrients were inconsistent with recommendations. Even when considering macronutrient intakes and severity of illness, several micronutrients were independent predictors of early growth. Low intake of folate was associated with poor weight and length gain. Furthermore, high iron supply was associated with poor growth in length and head circumference. Optimized early micronutrient supply may improve early growth in extremely preterm infants.

Sodium supply influences plasma sodium concentration and the risks of hyper- and hyponatremia in extremely preterm infants

Background:Hyper- and hyponatremia occur frequently in extremely preterm infants. Our purpose was to investigate plasma sodium (P-Na) concentrations, the incidence of hyper- and hyponatremia, and the impact of possible predisposing factors in extremely preterm infants.Methods:In this observational study, we analyzed data from the EXtremely PREterm (< 27 wk.) infants in Sweden Study (EXPRESS, n = 707). Detailed nutritional, laboratory, and weight data were collected retrospectively from patient records.Results:Mean ± SD P-Na increased from 135.5 ± 3.0 at birth to 144.3 ± 6.1 mmol/l at a postnatal age of 3 d and decreased thereafter. Fifty percent of infants had hypernatremia (P-Na > 145 mmol/l) during the first week of life while 79% displayed hyponatremia (P-Na < 135 mmol/l) during week 2. Initially, the main sodium sources were blood products and saline injections/infusions, gradually shifting to parenteral and enteral nutrition towards the end of the first week. The major determinant of P-Na and the risks of hyper- and hyponatremia was sodium supply. Fluid volume provision was associated with postnatal weight change but not with P-Na.Conclusion:The supply of sodium, rather than fluid volume, is the major factor determining P-Na concentrations and the risks of hyper- and hyponatremia.

Blood transfusions are not a risk factor fornecrotizing enterocolitis in extremely preterm infants

Background Transfusion practices are highly variable between hospitals and previous studies have suggested that blood transfusions may increase the risk of necrotizing enterocolitis (NEC). Aim To explore the association between blood transfusions and incidence of NEC in extremely preterm infants. Methods We used data from a Swedish population-based study including extremely preterm infants (<27 weeks) born between 2004–2007, (n = 602). All data on blood transfusions and haemoglobin (Hb) concentrations up to 28 days of age was collected for survivors. We performed a nested case-control study where two controls were chosen for each case of NEC (n = 21). Results During the first 28 days of life, infants received a median (25th-75th percentile) of 6 (3–9) blood transfusions resulting in 75 (44–120) ml/kg of blood. Predictors for receiving a higher volume of blood transfusions were days on respiratory support (R = 0.345, p < 0.001), hospital (R = 0.339, p < 0.001), low birth weight (R = -0.236, p < 0.001) and total steroid dose (R = 0.209, p < 0.001). Hb was not a significant predictor. Overall NEC incidence was 5.8%. There was no significant difference between NEC cases and controls in number of blood transfusions (p = 0.420), volume of blood transfused from birth to NEC diagnosis (p = 0.274), or during the 48 h preceding NEC diagnosis (p = 0.459). Conclusions Blood transfusions were given liberally in Sweden compared to other studied populations. Morbidity related variables, especially those related to respiratory illness, were significant predictors of blood transfusion. NEC incidence was comparable with other populations but no significant association was found between blood transfusions and NEC among these extremely preterm infants.

Hyperglycemia in Extremely Preterm Infants—Insulin Treatment, Mortality and Nutrient Intakes

Objective To explore the prevalence of hyperglycemia and the associations between nutritional intakes, hyperglycemia, insulin treatment, and mortality in extremely preterm infants. Study design Prospectively collected data from the Extremely Preterm Infants in Sweden Study (EXPRESS) was used in this study and included 580 infants born <27 gestational weeks during 2004‐2007. Available glucose measurements (n = 9850) as well as insulin treatment and nutritional data were obtained retrospectively from hospital records for the first 28 postnatal days as well as 28‐ and 70‐day mortality data. Results Daily prevalence of hyperglycemia >180 mg/dL (10 mmol/L) of up to 30% was observed during the first 2 postnatal weeks, followed by a slow decrease in its occurrence thereafter. Generalized additive model analysis showed that increasing parenteral carbohydrate supply with 1 g/kg/day was associated with a 1.6% increase in glucose concentration (P < .001). Hyperglycemia was associated with more than double the 28‐day mortality risk (P < .01). In a logistic regression model, insulin treatment was associated with lower 28‐ and 70‐day mortality when given to infants with hyperglycemia irrespective of the duration of the hyperglycemic episode (P < .05). Conclusions Hyperglycemia is common in extremely preterm infants throughout the first postnatal month. Glucose infusions seem to have only a minimal impact on glucose concentrations. In the EXPRESS cohort, insulin treatment was associated with lower mortality in infants with hyperglycemia. Current practices of hyperglycemia treatment in extremely preterm infants should be reevaluated and assessed in randomized controlled clinical trials.

Validation of the diagnosis of necrotising enterocolitis in a Swedish population-based observational study

The definition of necrotising enterocolitis (NEC) is based on clinical and radiological signs that can be difficult to interpret. The aim of the present study was to validate the incidence of NEC in the Extremely Preterm Infants in Sweden Study (EXPRESS)