title: Stopping Parenteral Nutrition for 3 Hours Reduces False Positives in Newborn Screening.
abstract: OBJECTIVE
  To evaluate effects of holding parenteral nutrition (PN) for 3 hours prior to newborn screening (NBS) on false-positive NBS rate for amino acids (AAs) in very low birth weight (VLBW) infants (birth weight <1500 g).
  
  
  METHODS
  We analyzed data from 12 567 consecutive births in 1 hospital between May 2010 and June 2013. VLBW infants were stratified into 3 groups: (1) infants without PN before NBS (no-PN group); (2) infants with early PN running at the time of NBS (early-PN group); and (3) infants with early-PN that were temporarily replaced by dextrose-containing intravenous fluid 3 hours prior to NBS (stop-PN group). We compared the false-positive rate for AA and cost effectiveness between the groups.
  
  
  RESULTS
  The false-positive rate for AA among 413 VLBW infants was significantly higher than infants with birth weight >1500 g (7.62% vs 0.05%; P < .001). There were no false-positive results for AA in the no-PN group. The false-positive rate for AA in the stop-PN group (2/65) was significantly lower than the early-PN group (29/245) (3.1% vs 11.8%; P = .037). The stop-PN group was more cost effective than early-PN group, saving $17.27 per infant screened ($5.53 vs $22.80) or $192.54 for each false-positive result for AA averted. Further reductions in inconclusive samples were also noted.
  
  
  CONCLUSIONS
  VLBW and early-PN are significant factors for false-positive results for AA. Holding PN containing AAs for 3 hours before NBS collection is a practical and cost-effective method to significantly reduce the false-positive rate for AA in VLBW infants.
authors.affiliation: Center for Human Genetics, University Hospitals Case Medical Center, Cleveland, OH; Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH.
authors.forename: Thipwimol
authors.initials: T
authors.lastname: Tim-Aroon
authors.affiliation: Division of Neonatology, Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, OH.
authors.forename: Heidi M
authors.initials: HM
authors.lastname: Harmon
authors.affiliation: Division of Neonatology, Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, OH.
authors.forename: Mary L
authors.initials: ML
authors.lastname: Nock
authors.affiliation: Division of Neonatology, Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, OH.
authors.forename: Sreekanth K
authors.initials: SK
authors.lastname: Viswanathan
authors.affiliation: Center for Human Genetics, University Hospitals Case Medical Center, Cleveland, OH; Department of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH. Electronic address: Shawn.McCandless@uhhospitals.org.
authors.forename: Shawn E
authors.initials: SE
authors.lastname: McCandless
mesh_terms: D000596:Amino Acids / Q000097:blood*; D015331:Cohort Studies; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008297:Male; D015997:Neonatal Screening / Q000379:methods*; D010288:Parenteral Nutrition / Q000379:methods*; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D000596:Amino Acids