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


METHODS
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).


CONCLUSIONS
In this intrapartum cohort, neither customized nor normalized population norms adequately identified neonates at risk of APO related to SGA.
Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas, USA. mmcostan@utmb.edu
Maged M
MM
Costantine
Yinglei
Y
Lai
Steven L
SL
Bloom
Catherine Y
CY
Spong
Michael W
MW
Varner
Dwight J
DJ
Rouse
Susan M
SM
Ramin
Steve N
SN
Caritis
Alan M
AM
Peaceman
Yoram
Y
Sorokin
Anthony
A
Sciscione
Brian M
BM
Mercer
John M
JM
Thorp
Fergal D
FD
Malone
Margaret
M
Harper
Jay D
JD
Iams
D001034:Apgar Score; D001724:Birth Weight; D016001:Confidence Intervals; D005260:Female; D047109:Fetal Development / Q000502:physiology; D005317:Fetal Growth Retardation / Q000503:physiopathology*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D007363:Intensive Care Units, Neonatal; D008297:Male; D010092:Oximetry / Q000379:methods; D011247:Pregnancy; D011248:Pregnancy Complications / Q000503:physiopathology*; D011256:Pregnancy Outcome; D011296:Prenatal Diagnosis / Q000379:methods; D012372:ROC Curve; D012016:Reference Values