Preterm Infant Growth Velocity Calculations: A Systematic Review

Area of Science:

• Neonatalogy
• Pediatric Growth Assessment
• Biostatistics

Background:

• Clinicians utilize diverse methods to evaluate preterm infant growth velocity.
• Assessing growth velocity is essential for monitoring infant development and health outcomes.

Purpose of the Study:

• To determine the numerical methods employed for calculating weight, length, and head circumference growth velocity in preterm infants.
• To identify the common units and approaches used in growth velocity calculations, such as grams/kilogram/day (g/kg/d), grams/day (g/d), centimeters/week (cm/week), and changes in z-scores.

Main Methods:

• A systematic review of studies measuring growth in preterm neonates was conducted using the Medline database.
• Studies published in English, French, German, and Spanish were included, adhering to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines.
• Detailed data extraction was performed on 151 studies reporting g/kg/d weight gain velocity.

Main Results:

• Grams/kilogram/day (g/kg/d) was the most frequent method for weight gain velocity (40%), followed by grams/day (g/d) (32%).
• Twenty-nine percent of studies reported changes in z-scores, indicating a shift towards standardized growth charts.
• Significant variability was observed in the starting points and denominators used for g/kg/d calculations, with 62% not reporting the kilogram denominator.

Conclusions:

• The heterogeneity in methodologies for calculating preterm infant growth velocity complicates inter-study comparisons.
• Lack of standardization poses a significant barrier to translating research findings into effective clinical practice for preterm infant care.
• A need exists for standardized protocols to ensure reliable and comparable assessment of infant growth trajectories.