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Equations describing percentiles for birth weight, head circumference, and length of preterm infants
W R Riddle1, S C DonLevy, B J Lafleur
1Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN 37232-2675, USA. bill.riddle@vanderbilt.edu
Insights
This study developed a growth chart for preterm infants born before 29 weeks gestation. Mathematical models accurately describe infant growth, aiding in the assessment of premature babies.
Area of Science:
- Neonatology
- Pediatric Growth and Development
Background:
- Assessing growth in extremely preterm infants is crucial for monitoring development.
- Existing growth charts may not adequately represent the growth patterns of infants born at very early gestations.
Purpose of the Study:
- To describe the growth trajectory of prematurely born infants.
- To create a specialized growth chart for infants born before 29 weeks of gestation.
Main Methods:
- Utilized a longitudinal database of 7,425 preterm infants (1985-1997).
- Collected data on birth weight, head circumference, and length.
- Determined multiple percentiles (3rd-97th) for mathematical modeling.
Main Results:
- Developed mathematical models: exponential for birth weight, linear for head circumference and length.
- Generated a preterm growth chart including 10th, 50th, and 90th percentiles.
- The chart covers birth weight, weight growth, head circumference, and length.
Conclusions:
- Mathematical models provide smooth and accurate percentile representations across gestational ages.
- The developed growth chart is suitable for assessing growth in extremely preterm infants.
Objective:
To describe growth of prematurely born infants and create a growth chart adequate to assess growth of infants with less than 29 completed weeks of gestation.
Study Design:
Birth weight, head circumference and length measurements of 7,425 liveborn preterm infants from 1985 to 1997 were retrieved from a longitudinal database maintained by the neonatology division. The 3rd, 5th, 10th, 15th, 25th, 50th, 75th, 85th, 90th, 95th and 97th percentiles of each measurement were determined and used for mathematical modeling.
Results:
Birth weight was described with an exponential function while head circumference and length were described with linear functions. A preterm growth chart for the 10th, 50th and 90th percentiles for birth weight, weight growth, head circumference and length was generated.
Conclusion:
The mathematical models of growth provide smooth representations of the percentiles across gestational ages.
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