Neonatal Macrosomia is an Interfering Factor for Analytes on the Colorado State Newborn Screen.

Abstract

PURPOSE:

Neonatal macrosomia is a known complication of maternal obesity and gestational diabetes, and it is a risk factor for obesity and diabetes in offspring. Amino acids and acylcarnitines are biomarkers for obesity in children and adults. These analytes, which are also routinely obtained on the newborn screen, have not been well-characterized in macrosomic newborns. The impact of macrosomia on rates of false-positive results in the newborn screen has also not been well-studied. We test the hypothesis that macrosomia is an interfering factor for amino acids and/or acylcarnitines on the newborn screen.

METHODS:

Newborn screening analytes determined by tandem mass spectroscopy were obtained from the Colorado Department of Public Health and Environment archives (2016-2018). This included metabolite concentrations obtained at 24-72 hours of life from newborns with birth weight 2500 to 3999 g (nonmacrosomic, n = 131 896) versus 4000 to 8000 g (macrosomic, n = 7806). Mother/infant phenotypic data were limited to information provided on the newborn screening dried blood spot card. Data were analyzed using Student t-test and chi-squared analysis.

RESULTS:

Macrosomic newborns had elevations in C2, C3, dicarboxylic, and long-chain acylcarnitines (specifically C16 and C18 species). C3 and C18:1 were 2 to 3 times more likely to be above predetermined state cutoffs in macrosomic versus nonmacrosomic newborns (both male and female).

MAIN CONCLUSIONS:

Macrosomia is an interfering factor for the analytes C3 and C18:1, leading to higher risk of false-positive results for methylmalonic/propionic acidemia and carnitine palmitoyl transferase type 2 deficiency, respectively. Analyte patterns found in macrosomic neonates correspond with similar analyte patterns in obese children and adults.

• Authors: Erica L Wright, Peter R Baker
• Journal: The Journal of clinical endocrinology and metabolism (J Clin Endocrinol Metab) Vol. 105 Issue 3 (03 01 2020) ISSN: 1945-7197 [Electronic] United States
• PMID: 32126138 (Publication Type: Journal Article)
• Copyright: © Endocrine Society 2020. All rights reserved. For permissions, please e-mail: [email protected].

Chemical References

• acylcarnitine
• Carnitine O-Palmitoyltransferase
• Carnitine

Topics

• Adult
• Amino Acid Metabolism, Inborn Errors (diagnosis)
• Carnitine (analogs & derivatives, blood)
• Carnitine O-Palmitoyltransferase (deficiency)
• Colorado
• False Positive Reactions
• Female
• Fetal Macrosomia (blood, complications)
• Humans
• Infant, Newborn
• Infant, Newborn, Diseases (diagnosis)
• Male
• Metabolism, Inborn Errors (diagnosis)
• Neonatal Screening (methods)
• Pediatric Obesity (diagnosis)
• Pregnancy
• Propionic Acidemia (diagnosis)
• Tandem Mass Spectrometry