title: Clinical Validation of the INTERGROWTH-21st Standards of Fetal Abdominal Circumference for the Prediction of Small-for-Gestational-Age Neonates in Italy.
abstract: OBJECTIVE
  To compare the accuracy of the INTERGROWTH-21st (IG-21) with the Italian Society of Ultrasound in Obstetrics and Gynecology (SIEOG) abdominal circumference (AC) standards in the detection of small-for-gestational-age (SGA) fetuses in a high-risk population.
  
  
  METHODS
  Our study included all pregnant patients with an increased risk of placental insufficiency that were seen in two Italian university hospitals between 2014 and 2015. The accuracy of IG-21 and SIEOG AC standards in the detection of SGA neonates was analyzed by means of the area under the receiver operating characteristic curve (ROC-AUC) at 4 gestational age intervals (24-27, 28-31, 32-35, >35 weeks).
  
  
  RESULTS
  We enrolled 428 patients (278 Italians). There was no significant difference between the ROC-AUC of AC according to IG-21 and SIEOG standards for all birthweight thresholds and gestational intervals that were considered. The diagnostic performance was similar in Italian and non-Italian patients. The accuracy was, however, limited, with values of ROC-AUC ranging between 0.80 and 0.89.
  
  
  CONCLUSIONS
  The IG-21 and SIEOG AC standards are interchangeable for the diagnosis of SGA fetuses. The diagnostic accuracy is, however, limited. We provide figures that can be used to stratify the probability that an infant will be SGA in an obstetric population at increased risk of growth restriction.
authors.affiliation: Department of Obstetrics and Gynecology, University of Bologna, Bologna, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Bellussi
authors.forename: Ilaria
authors.initials: I
authors.lastname: Cataneo
authors.forename: Silvia
authors.initials: S
authors.lastname: Visentin
authors.forename: Giuliana
authors.initials: G
authors.lastname: Simonazzi
authors.forename: Jacopo
authors.initials: J
authors.lastname: Lenzi
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Fantini
authors.forename: Stefano
authors.initials: S
authors.lastname: Mimmi
authors.forename: Erich
authors.initials: E
authors.lastname: Cosmi
authors.forename: Gianluigi
authors.initials: G
authors.lastname: Pilu
mesh_terms: D000005:Abdomen / Q000000981:diagnostic imaging* / Q000196:embryology / Q000254:growth & development; D047109:Fetal Development; D005865:Gestational Age; D006801:Humans; D007236:Infant, Small for Gestational Age; D007558:Italy; D016216:Ultrasonography, Prenatal / Q000592:standards*
keywords: Abdominal circumference; Fetal growth restriction; INTERGROWTH-21st; Small for gestational age