Individualized Postnatal Growth Trajectories for Preterm Infants.

BACKGROUND: Growth of preterm infants is monitored using fetal charts despite individual trajectories being downshifted postnatally by adaptational processes. The study aims to compare different approaches to create individualized postnatal trajectories. METHODS: Three approaches to achieve growth similar to healthy term infants at 42+0/7 weeks postmenstrual age (PMA) on World Health Organization growth standards (WHOGS) (target weight) were tested by comparing trajectories obtained by: 1) following birth percentiles (Birth-Weight-Percentile Approach); 2) following percentiles achieved at day of life 21 (Postnatal-Percentile Approach); 3) using day-specific fetal median growth velocities starting at day of life 21 (Fetal-Median-Growth Approach [FMGA]). The primary outcome was delta weight (ΔW), defined as difference between target weight (WHOGS) at 42+0/7 weeks and weight predicted by trajectories. The secondary outcome was ΔW vs %fat mass in a cohort of 20 disease-free surviving very low-birth-weight infants. RESULTS: Birth-Weight-Percentile and Postnatal-Percentile Approach showed high ΔW; FMGA alone reduced ΔW. Introducing a factor to FMGA to reflect the transition to extrauterine conditions (Growth-Velocity Approach [GVA]) minimized ΔW. GVA merged with target and best normalized for body composition related to ΔW. CONCLUSIONS: GVA provides an evidence-based approach for individualized growth trajectories. GVA is based on physiologic data and that healthy preterm infants adjust their postnatal trajectory below their birth percentile. GVA may reflect a biologic principle because it matches consistently with WHOGS at 42+0/7 weeks for all preterm infants from 24 to 34 weeks. This concept could become a bedside tool to aid clinicians in monitoring growth, guiding nutrition, and minimizing chronic adult disease risks as a consequence of unguided, inappropriate growth.

Length Normalized Indices for Fat Mass and Fat-Free Mass in Preterm and Term Infants during the First Six Months of Life.

OBJECTIVE: Postnatal tissue accretion in preterm infants differs from those in utero, affecting body composition (BC) and lifelong morbidity. Length normalized BC data allows infants with different body lengths to be compared and followed longitudinally. This study aims to analyze BC of preterm and term infants during the first six months of life. METHODS: The BC data, measured using dual energy X-ray absorptiometry, of 389 preterm and 132 term infants from four longitudinal studies were combined. Fat-mass/length² (FMI) and fat-free mass/length² (FFMI) for postmenstrual age were calculated after reaching full enteral feeding, at term and two further time points up to six months corrected age. RESULTS: Median FMI (preterm) increased from 0.4 kg/m² at 30 weeks to 2.5, 4.3, and 4.8 kg/m² compared to 1.7, 4.7, and 6 kg/m² in term infants at 40, 52, and 64 weeks, respectively. Median FFMI (preterm) increased from 8.5 kg/m² (30 weeks) to 11.4 kg/m² (45 weeks) and remained constant thereafter, whereas term FFMI remained constant at 11 kg/m² throughout the tested time points. CONCLUSION: The study provides a large dataset of length normalized BC indices. Followed longitudinally, term and preterm infants differ considerably during early infancy in the pattern of change in FMI and FFMI for age.

Morphine for elective endotracheal intubation in neonates: a randomized trial [ISRCTN43546373].

BACKGROUND: Elective endotracheal intubations are still commonly performed without premedication in many institutions. The hypothesis tested in this study was that morphine given prior to elective intubations in neonates would decrease fluctuations in vital signs, shorten the duration of intubation and reduce the number of attempts. METHODS: From December 1999 to September 2000, infants of all gestations admitted to a level III neonatal intensive care unit and requiring an elective endotracheal intubation were randomly assigned to receive morphine 0.2 mg/kg IV or placebo 5 minutes before intubation. Duration of severe hypoxemia (HR< 90/min and Sp02<85%), duration of procedure, duration of hypoxemia (Sp02<85%), number of attempts and change in mean blood pressure were compared between groups. RESULTS: 34 infants (median 989 g and 28 weeks gestation) were included. The duration of severe hypoxemia was similar between groups. Duration of procedure, duration of hypoxemia, number of attempts and increases in mean blood pressure were also similar between groups. 94% of infants experienced bradycardia during the procedure. CONCLUSION: We failed to demonstrate the effectiveness of morphine in reducing the physiological instability or time needed to perform elective intubations. Alternatives, perhaps with more rapid onset of action, should be considered.