Birth weight percentile charts based on daily measurements for very preterm male and female infants at the age of 154--223 days

Voigt, Manfred
Rochow, Niels
Straube, Sebastian
Briese, Volker
Olbertz, Dirk
Jorch, Gerhard

¹Institute for Perinatal Auxology, Klinikum Südstadt, Rostock, Germany
²Division of Neonatology, Department of Pediatrics, McMaster University, Hamilton, L8N 325, Ontario, Canada
³Department of Occupational and Social Medicine, University of Göttingen, Germany
⁴Department of Obstetrics and Gynecology, University of Rostock, Germany
⁵Department of Neonatology, Klinikum Südstadt, Rostock, Germany
⁶Department of Pediatrics, University of Magdeburg, Germany
^aManfred Voigt and Niels Rochow contributed equally.

^*Corresponding author: Dr. med. Niels Rochow Institute for Perinatal Auxology Südring 81 18059 Rostock Germany Tel: + 49 (381) 4401–5575 Fax: +49 (381) 4401–5579 E-mail: [email protected]

The authors stated that there are no conflicts of interest regarding the publication of this article.

Received June 19, 2009. Revised October 2, 2009. Accepted October 12, 2009. Previously published online February 2, 2010.

Journal of Perinatal Medicine 38(3):p 289-295, May 2010.

Objective

Birth weight percentiles based on weekly measurements are used to assess the nutritional status of preterm infants. However, as preterm infants exhibit a rapid growth rate (up to 20 g/kg/day), their body weight can increase by 15% per week. We calculated birth weight percentiles based on daily measurements, to more precisely classify very preterm infants (gestational age of 154–223 days).

Methods

Data of 23,864 (10,720 females and 13,144 males) very preterm singleton infants with a gestational age of 154–223 days (22–31 completed weeks) were retrieved from the German perinatal statistics of 1995–2000. Percentile curves based on the empirical birth weight data were subjected to three statistical smoothing procedures: cubic regression, local regression (LOESS smoothing), and the LMS method.

Results

Smoothing of the birth weight percentiles using cubic regression produced the smallest residual variance.

Conclusion

Birth weight percentiles based on daily averages allow a more precise assessment of the somatic development of preterm infants.