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Premature Infant Weight and Height #368

yishuanwu opened this issue May 24, 2019 · 1 comment


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commented May 24, 2019

Hi all:

I'd like to share some of my notes on the PK-Sim preterm population.

The PK-Sim preterm neonate population is based on the publication by Claassen et al. (2015):

The description for establishing body weight and height was a bit vague to me. It referenced the 2003 Fenton premature growth charts publication, some data from Australia and Pediatrix Medical Group, but also included the overall growth chart for an Asian country (Taiwan), and growth curves from 1960s which had been determined to be obsolete as neonates are getting heavier.

I was perplexed because an updated 2013 Fenton premature growth charts publication was available at the time of Claassen's publication. This standard is based on more recent publications (1999-2010), include many more subjects, and is more focused on the European population (Germany, USA, Canada, Australia, Scotland, and Italy), and it transitions nicely to the WHO growth curves. While Taiwan is a first world country, Asians were not a significant proportion of the subjects in my data so I prefer to assess the comparison to more Caucasian-based neonates.

In addition, the Claassen paper did not describe how the Weight and Height were linked for each individual. None of the references would be appropriate for linking weight and height. As the Fenton papers also lack descriptions on linking weight and height, I used the Olsen 2015 paper for preterm BMI. This publication did not smooth over the transition to WHO growth curve, so there is a little dip connecting the growth curve to term infant growth curve at 53 weeks.

To investigate, I did a quick exploration:

In PK-Sim, I simulated a population of preterm infants:
GA 24-36 weeks
PNA 0-365 days
SEX 50% female
N = 10,0000

In the following graphs, the solid lines are medians, and the dashed lines are 3 and 97%tiles. The dots are the simulated subjects, the lighter colors are the quantile curves for the references, and the darker colors are the quantile curves for the simulated subjects:





Thank you for reading this post!


  1. Claassen 2015: PMID 26323410
  2. Fenton 2003: PMID 14678563
  3. Fenton 2013: PMID 23601190
  4. Olsen 2015: PMID 25687149
  5. CDC growth chart:
  6. WHO growth chart:

@msevestre msevestre transferred this issue from Open-Systems-Pharmacology/PK-Sim Jul 30, 2019


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commented Aug 1, 2019

Thanks Yishuanwu, that looks very interesting! Best, Tobias

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