Archana Bottu, MD, Shabih Manzar, MD, MPH

Summary: 

This brief report describes a three-pronged scoring (TPS) system to monitor weekly postnatal growth in preterm infants. The TPS was developed by combining growth velocity (GV), weight gain ratio (WGR), and a delta z-score (D Z). A score of 3 is concerning, a score of 4-5 is reassuring, and a score of 6 is appropriate. The TPS provides a model for developing clinical decision support. 

Adequate growth is particularly important for preterm infants, monitored by weight, height, and head circumference plotted on growth charts. In this paper, we looked at growth pertaining to weight. 

Acronyms and Abbreviations: 

• GV – Growth velocity 
• WGR – Weight gain ratio 
• ZSD –Z-score difference 

Most of the studies on growth monitoring use Z-scores.(1) Rochow et al. (2) have shown that the inclusion of weight gain ratio (WGR) in addition to delta z-score (D Z) or the difference between z-scores (ZSD) is a better way to monitor postnatal growth. Growth velocity (GV) is the most common indicator to monitor growth.(3) The diagram below uses a three-pronged score, combining GV, WGR, and ZSD, to assess growth more thoroughly in a preterm infant. Example: Figure 1 presents an example of calculating GV, WGR, and ZSD. 

Figure 1 presents an example of calculating GV, WGR, and ZSD. 

In conclusion, a three-pronged score may better evaluate weekly postnatal growth in preterm infants. This score could be used as a model for developing clinical decision support. 

References: 

1. de Onis M, Blössner M. The World Health Organization Global Database on Child Growth and Malnutrition: methodology and applications. Int J Epidemiol. 2003;32(4):518-526. doi:10.1093/ije/dyg099 
2. Rochow N, Landau-Crangle E, So HY, et al. Z-score differences based on cross-sectional growth charts do not reflect the growth rate of very low birth weight infants. PLoS One. 2019;14(5): e0216048. Published 2019 May 7. doi: 10.1371/ journal.pone.0216048 
3. Patel AL, Engstrom JL, Meier PP, Jegier BJ, Kimura RE. Calculating postnatal growth velocity in very low birth weight (VLBW) premature infants. J Perinatol 2009; 29(9): 618-22 

Authors’ contribution: Dr. Manzar and Dr. Bottu conceptualized the study and wrote the draft. 

Completing Interests Statement: Authors have no competing interests to declare. 

Financial Disclosure Statement: Authors have no funding to disclose.