Niels Rochow

Target Fortification of Breast Milk with Fat, Protein, and Carbohydrates for Preterm Infants

OBJECTIVES Fortification of breast milk is an accepted practice for feeding very low birth weight infants, however, fixed dosage enhancement does not address variations in native breast milk. This could lead to deficiencies in calories and macronutrients. We therefore established the infrastructure for target fortification in breast milk by measuring and adjusting fat, protein, and carbohydrate content daily. We analyzed nutrient intake, growth, and safety variables. STUDY DESIGN Each 12-hour batch of breast milk was analyzed using near-infrared spectroscopy. Macronutrients were individually added to routine fortification to achieve final contents for fat (4.4 g), protein (3 g), and carbohydrates (8.8 g) (per 100 mL). Fully breast milk fed healthy very low birth weight infants (<32 weeks) were fed the fortified breast milk for at least 3 weeks. Matched pair analysis of 20 infants fed routinely fortified breast milk was performed using birth weight, gestational age, and postnatal age. RESULTS All 650 pooled breast milk samples required at least 1 macronutrient adjusted. On average, 0.3 ± 0.4 g of fat, 0.7 ± 0.2 g of protein, and 1.2 ± 0.2 g of carbohydrate were added. Biochemistry was normal in the 10 target fortified infants (birth weight: 860 ± 309 g, 26.3 ± 1.6 weeks gestational age); weight gain was 19.9 ± 2.7 g/kg/d; and milk intake was 147 ± 5 mL/kg/d (131 ± 16 kcal/kg/d). Osmolality of fortified breast milk was 436 ± 13 mOsmol/kg. Matched pair analysis of infants indicated a higher milk intake (155 ± 5 mL/kg/d) but similar weight gain (19.7 ± 3.3 g/kg/d). No adverse event was observed. The linear relationship between milk intake and weight gain observed in study babies but not seen in matched controls may be related to the variable composition of breast milk. CONCLUSIONS Daily target fortification can be safely implemented in clinical routine and may improve growth.

Rapid measurement of macronutrients in breast milk: How reliable are infrared milk analyzers? *

SUMMARY Background & aims Significant biological variation in macronutrient content of breast milk is an important barrier that needs to be overcome to meet nutritional needs of preterm infants. To analyze macronutrient content, commercial infrared milk analyzers have been proposed as efficient and practical tools in terms of efficiency and practicality. Since milk analyzers were originally developed for the dairy industry, they must be validated using a significant number of human milk samples that represent the broad range of variation in macronutrient content in preterm and term milk. Aim of this study was to validate two milk analyzers for breast milk analysis with reference methods and to determine an effective sample pretreatment. Current evidence for the influence of (i) aliquoting, (ii) storage time and (iii) temperature, and (iv) vessel wall adsorption on stability and availability of macronutrients in frozen breast milk is reviewed. Methods Breast milk samples (n = 1188) were collected from 63 mothers of preterm and term infants. Milk analyzers: (A) Near-infrared milk analyzer (Unity SpectraStar, USA) and (B) Mid-infrared milk analyzer (Miris, Sweden) were compared to reference methods, e.g. ether extraction, elemental analysis, and UPLC-MS/MS for fat, protein, and lactose, respectively. Results For fat analysis, (A) measured precisely but not accurately (y = 0.55x + 1.25, r2 = 0.85), whereas (B) measured precisely and accurately (y = 0.93x + 0.18, r2 = 0.86). For protein analysis, (A) was precise but not accurate (y = 0.55x + 0.54, r2 = 0.67) while (B) was both precise and accurate (y = 0.78x + 0.05, r2 = 0.73). For lactose analysis, both devices (A) and (B) showed two distinct concentration levels and measured therefore neither accurately nor precisely (y = 0.02x + 5.69, r2 = 0.01 and y = −0.09x + 6.62, r2 = 0.02 respectively). Macronutrient levels were unchanged in two independent samples of stored breast milk (−20 °C measured with IR; −80 °C measured with wet chemistry) over a period of 14 months. Conclusions Milk analyzers in the current configuration have the potential to be introduced in clinical routine to measure fat and protein content, but will need major adjustments.

An Integrated Array of Microfluidic Oxygenators as a Neonatal Lung Assist Device: In Vitro Characterization and In Vivo Demonstration

A miniaturized oxygenator device that is perfused like an artificial placenta via the umbilical vessels may have significant potential to save the lives of newborns with respiratory insufficiency. Recently we presented the concept of an integrated modular lung assist device (LAD) that consists of stacked microfluidic single oxygenator units (SOUs) and demonstrated the technical details and operation of SOU prototypes. In this article, we present a LAD prototype that is designed to accommodate the different needs of term and preterm infants by permitting changing of the number of parallel-stacked microfluidic SOUs according to the actual body weight. The SOUs are made of polydimethylsiloxane, arranged in parallel, and connected though 3D-printed polymeric interconnects to form the LAD. The flow characteristics and the gas exchange properties were tested in vitro using human blood. We found that the pressure drop of the LAD increased linearly with flow rate. Gas exchange rates of 2.4-3.8 μL/min/cm(2) (0.3-0.5 mL/kg/min) and 6.4-10.1 μL/min/cm(2) (0.8-1.3 mL/kg/min) for O2 and CO2 , respectively, were achieved. We also investigated protein adsorption to provide preliminary information on the need for application of anticoagulant coating of LAD materials. Albumin adsorption, as measured by gold staining, showed that surface uptake was evenly distributed and occurred at the monolayer level (>0.2 μg/cm(2) ). Finally, we also tested the LAD under in vivo conditions using a newborn piglet model (body weight 1.65-2.0 kg). First, the effect of an arteriovenous bypass via a carotid artery-to-jugular vein shortcut on heart rate and blood pressure was investigated. Heart rate and mean arterial blood pressure remained stable for extracorporeal flow rates of up to 61 mL/kg/min (101 mL/min). Next, the LAD was connected to umbilical vessels (maximum flow rate of 24 mL/min [10.4 mL/kg/min]), and O2 gas exchange was measured under hypoxic conditions (Fi O2  = 0.15) and was found to be 3.0 μL/min/cm(2) . These results are encouraging and support the feasibility of an artificial placental design for an LAD.

Quantification of lactose content in human and cow's milk using UPLC-tandem mass spectrometry.

A sensitive, accurate, and specific quantitative UPLC-MS/MS method was developed for lactose measurement of cows and human milk and validated with cows milk samples certified by an external laboratory. The new method employs only a dilution of raw cows and human milk for simple preparation with no need to remove protein and fat prior to analysis with UPLC-MS/MS. It was operated in negative mode to detect lactose molecules and labeled (13)C(12)-lactose with the highest sensitivity. The principle advantages of the new LC-MS/MS method were: completed lactose determination in 5 min, absolute recovery of 97-107%, lower limit of detection <5 ng/L, and 99% linearity over the concentration range of 0.7-4.4 mg/L for both cows and human milk. The mean lactose concentration of 51 human milk samples was measured as 56.8 ± 5.5 g/L ranging from 43 to 65 g/L. The described method represents validated lactose analysis with high accuracy and precision for a routine lactose determination in raw human milk.

Physiological adjustment to postnatal growth trajectories in healthy preterm infants

Background:International guidelines suggest that growth of preterm infants should match intrauterine rates. However, the trajectory for extrauterine growth may deviate from the birth percentile due to an irreversible, physiological loss of extracellular fluid during postnatal adaptation to extrauterine conditions. To which “new” physiological growth trajectory preterm infants should adjust to after completed postnatal adaptation is unknown. This study analyzes the postnatal growth trajectories of healthy preterm infants using prospective criteria defining minimal support, as a model for physiological adaptation.Methods:International, multi-center, longitudinal, observational study at five neonatal intensive care units (NICUs). Daily weights until day of life (DoL) 21 of infants with undisturbed postnatal adaptation were analyzed (gestational ages: (i) 25–29 wk, (ii) 30–34 wk).Results:981 out of 3,703 admitted infants included. Maximum weight loss was 11% (i) and 7% (ii) by DoL 5, birth weight regained by DoL 15 (i) and 13 (ii). Infants transitioned to growth trajectories parallel to Fenton chart percentiles, 0.8 z-scores below their birth percentiles. The new trajectory after completed postnatal adaptation could be predicted for DoL 21 with R2 = 0.96.Conclusion:This study provides a robust estimate for physiological growth trajectories of infants after undisturbed postnatal adaptation. In the future, the concept of a target postnatal trajectory during NICU care may be useful.

Challenges in breast milk fortification for preterm infants.

Purpose of reviewTo outline new evidence published from 2013 to 2014 about breast milk fortification in preterm infants. Recent findingsBreast milk is the feeding choice for preterm infants because of its immunoprotective properties. However, breast milks nutrient content is not sufficient for preterm infants, and interindividual variation is high. The variation challenges standard fortification, which assumes a standard breast milk composition. Two new fortification strategies (adjustable fortification and target fortification) optimize macronutrient intake and improve growth. Adjustable fortification uses blood urea nitrogen levels to adjust fortifier strength. Target fortification analyzes breast milk and fortifies macronutrients individually to achieve targeted intake. Its feasibility is shown in clinical routine. Current breast milk analyzers used for target fortification achieve acceptable precision for protein and fat but not for lactose and energy. Evidence of benefits for postdischarge breast milk fortification is lacking. Eliminating cows milk products and feeding exclusively breast milk may decrease the occurrence of feeding intolerance and necrotizing enterocolitis. To facilitate exclusively breast milk diets, a collaboration of prenatal, nutrition and lactation stakeholders is key. Fortification increases osmolality; however, safety cutoffs to prevent necrotizing enterocolitis are unclear. There is also new evidence that composition and structure of various macronutrients and micronutrients affect growth and development, and might play a role in future fortification concepts. SummaryRecent research focuses on the variability of breast milk composition, its impact on postnatal growth patterns and the usefulness of target fortification. As well, diets exclusively composed of human milk are a promising approach to improve feeding tolerance. For safe fortification, osmolality cutoff levels are needed.

Fortification of breast milk in VLBW infants: Metabolic acidosis is linked to the composition of fortifiers and alters weight gain and bone mineralization

BACKGROUND & AIMS Study objectives were to test (a) whether increased incidence of metabolic acidosis (MA) was caused by introduction of a new commercially available fortifier for breast milk, (b) if so, whether its modification would decrease the incidence of MA and (c) to analyze the impact of MA on growth. METHODS Double-blind randomized design. Healthy breast-fed infants (≤34 gestational weeks). Primary outcome measure was incidence of MA (BE < -6.0 mmol/L). Secondary outcome measures were growth, bone mineral content (BMC), vital signs, treatment with sodium hydrogen carbonate and Ca and laboratory parameters (pH, pCO₂, HCO₃⁻, electrolytes). RESULTS Part 1 (comparison of standard (SF) and new fortifier (NF)): Interim analysis showed MA in 1 out of 7 (SF) and 7 out of 8 (NF) infants, p = 0.01; therefore the study was interrupted; subsequently the fortifier was adapted by modifying mineral components. Part 2 (comparison of SF and reformulated fortifier (RF)): MA occurred in 3 out of 15 (SF) and 6 out of 19 (RF), p = 0.7. When data of all infants studied, those with MA had lower mean weight gain (median: 9 vs. 21 g/kg/d, p < 0.01) and lower BMC (1.6% vs. 1.9% BMC/lean, p = 0.04) at discharge. CONCLUSIONS When fed fortified breast milk, mild MA spontaneously may develop in 20-30% of VLBW infants. A fortifier with an inappropriate composition may increase the severity and frequency of MA. Our data show that weight gain and BMC seem to be related to acid-base homeostasis. It may be speculated that inadequate growth of fully fed preterm infants is triggered more often by imbalances of acid-base status than previously expected.

[New percentile values for the anthropometric dimensions of singleton neonates: analysis of perinatal survey data of 2007-2011 from all 16 states of Germany].

AIM The aim of this study was to derive percentile values for birth weight, length, head circumference, and weight for length for singleton neonates based on the German perinatal survey of 2007-2011 (using data from all 16 states of Germany). We also compared these new percentile values with the percentile values of 1995-2000 that so far have been considered standard values. MATERIAL AND METHODS Data of 3 187 920 singleton neonates from the German perinatal survey of the years 2007-2011 were kindly provided to us by the AQUA Institute in Göttingen, Germany. Sex specific percentile values were calculated using cumulative frequencies. Percentile values at birth were computed for the 3(rd), 10(th), 25(th), 50(th), 75(th), 90(th), and 97(th) percentiles for 21-43 completed weeks of gestation. Percentile curves and tabulated values for the years 2007-2011 were compared with the published values of 1995-2000. RESULTS AND DISCUSSION Overall the new percentile curves closely resemble the previous ones. Minimal differences can be found for the 10(th) percentile and generally for early weeks of gestation. Values for the 10(th) percentile in the 2007-2011 dataset are somewhat higher than values of 1995-2000 for birth weight, length, and weight for length. CONCLUSIONS We recommend the use of these new percentile values instead of the old ones.

Dependence of neonatal small and large for gestational age rates on maternal height and weight--an analysis of the German Perinatal Survey.

Abstract Neonatal anthropometric data reflect intrauterine development and correlate with postnatal outcome. Therefore, classification of neonates by body dimensions, using gestational age-adjusted population percentiles, is clinically practiced. However, neonatal anthropometric variables are also influenced by maternal constitution and the extent of this influence is currently unknown. We analyzed small for gestational age (SGA) and large for gestational age (LGA) rates according to maternal height and weight. We used data of about 2.3 million singleton pregnancies from the German Perinatal Survey of 1995–2000. A close correlation between maternal and neonatal anthropometric data was found; SGA rates were inversely proportional and LGA rates were directly proportional to maternal height, weight, and body mass index. Neonates of small and light mothers (<155 cm, <50 kg) had, according to the presently used classification scheme, an SGA rate of 25.3% and an LGA rate of 1.7%, respectively. Newborns to tall and heavy women (>179 cm, >89 kg) had a much lower SGA rate (3.1%) and a much higher LGA rate (30.6%). Neonatal body length and head circumference depended on maternal stature in a similar way. Some neonates who are “appropriate” for their gestational age in that they achieve their genetically determined growth potential are therefore apparently misclassified as SGA or LGA.

Target Fortification of Breast Milk: How Often Should Milk Analysis Be Done?

Target fortification (TFO) reduces natural macronutrient variation in breast milk (BM). Daily BM analysis for TFO increases neonatal intensive care unit work load by 10–15 min/patient/day and may not be feasible in all nurseries. The variation of macronutrient intake when BM analysis is done for various schedules was studied. In an observational study, we analyzed 21 subsequent samples of native 24-h BM batches, which had been prepared for 10 healthy infants (gestational age 26.1 ± 1.3 weeks, birth weight: 890 ± 210 g). Levels of protein and fat (validated near-infrared milk analyzer), as well as lactose (UPLC-MS/MS) generated the database for modelling TFO to meet recommendations of European Society for Paediatric Gastroenterology Hepatology and Nutrition. Intake of macronutrients and energy were calculated for different schedules of BM measurements for TFO (n = 1/week; n = 2/week; n = 3/week; n = 5/week; n = 7/week) and compared to native and fixed dose fortified BM. Day-to-day variation of macronutrients (protein 20%, carbohydrate 13%, fat 17%, energy 10%) decreased as the frequency of milk analysis increased and was almost zero for protein and carbohydrate with daily measurements. Measurements two/week led to mean macronutrient intake within a range of ±5% of targeted levels. A reduced schedule for macronutrient measurement may increase the practical use of TFO. To what extent the day-to-day variation affects growth while mean intake is stable needs to be studied.