Population versus customized fetal growth norms and adverse outcomes in an intrapartum cohort

Am J Perinatol. 2013 Apr;30(4):335-41. doi: 10.1055/s-0032-1324708. Epub 2012 Aug 14.


Objective: To compare population versus customized fetal growth norms in identifying neonates at risk for adverse outcomes (APO) associated with small for gestational age (SGA).

Study design: Secondary analysis of an intrapartum fetal pulse oximetry trial in nulliparous women at term. Birth weight percentiles were calculated using ethnicity- and gender-specific population norms and customized norms (Gardosi).

Results: Of the studied neonates, 508 (9.9%) and 584 (11.3%) were SGA by population (SGApop) and customized (SGAcust) norms, respectively. SGApop infants were significantly associated with a composite adverse neonatal outcome, neonatal intensive care admission, low fetal oxygen saturation, and reduced risk of cesarean delivery; both SGApop and SGAcust infants were associated with a 5-minute Apgar score < 4. The ability of customized and population birth weight percentiles in predicting APO was poor (12 of 14 APOs had area under the curve of <0.6).

Conclusion: In this intrapartum cohort, neither customized nor normalized population norms adequately identified neonates at risk of APO related to SGA.

Publication types

  • Comparative Study
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Apgar Score*
  • Birth Weight
  • Confidence Intervals
  • Female
  • Fetal Development / physiology
  • Fetal Growth Retardation / physiopathology*
  • Gestational Age
  • Humans
  • Infant, Newborn
  • Infant, Small for Gestational Age*
  • Intensive Care Units, Neonatal
  • Male
  • Oximetry / methods
  • Pregnancy
  • Pregnancy Complications / physiopathology*
  • Pregnancy Outcome*
  • Prenatal Diagnosis / methods
  • ROC Curve
  • Reference Values

Grant support