title: Prediction of small-for-gestational-age status by symphysis-fundus height: a registry-based population cohort study.
abstract: OBJECTIVE
  To develop a chart for risk of small-for-gestational-age (SGA) at birth depending on deviations in symphysis-fundus (SF) height values for gestational age during pregnancy weeks 24-42.
  
  
  METHODS
  Registry-based population cohort study.
  
  
  METHODS
  Antenatal clinics, Västra Götaland County, Sweden, 2005-2010.
  
  
  METHODS
  The study included 42 018 women with ultrasound-dated singleton pregnancies who delivered at Sahlgrenska University Hospital. Data (including 282 713 SF height measurements) were extracted from the hospital's computerised obstetric database.
  
  
  METHODS
  Linear and binary regression analyses were used to derive prediction models with deviations in birthweight (BW) and SF height by gestational age as dependent and independent variables, respectively. Receiver operating characteristic curves were generated to evaluate the predictive value of the model in detecting SGA.
  
  
  METHODS
  Birthweight and small-for-gestational-age.
  
  
  RESULTS
  Symphysis-fundus height accounted for 3% of individual BW variance at 24 weeks, increasing gradually to 20% at 40 weeks. Maternal factors explained an additional 10 percentage points of BW variance. Receiver operating characteristic curves confirmed that SF height was a stronger SGA predictor in late than in early pregnancy. Using an SGA relative risk cut-off limit of ≥2-fold, the overall sensitivity was 50% and the overall specificity 80%. Only the most recent SF measurement was useful in predicting BW deviation; previous measurements added nothing to the predictive value.
  
  
  CONCLUSIONS
  The ability of SF measurements to detect SGA status at birth increases with gestational age. Only the most recent SF measurement has predictive value; a static or falling pattern of SF values did not increase SGA likelihood.
  
  
  CONCLUSIONS
  New SF curves predict SGA best in late pregnancy; only the most recent SF measurement has predictive value.
authors.affiliation: Departments of Obstetrics and Gynaecology, Women's and Children's Division, Oslo University Hospital, Oslo, Norway.|Department of International Public Health, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: Asd
authors.initials: A
authors.lastname: Pay
authors.affiliation: Department of International Public Health, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: J F
authors.initials: JF
authors.lastname: Frøen
authors.affiliation: Departments of Obstetrics and Gynaecology, Women's and Children's Division, Oslo University Hospital, Oslo, Norway.|Faculty of Medicine, University of Oslo, Oslo, Norway.
authors.forename: A C
authors.initials: AC
authors.lastname: Staff
authors.affiliation: Department of Obstetrics and Gynaecology, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg, Sweden.|Department of Genes and Environment, Norwegian Institute of Public Health, Oslo, Norway.
authors.forename: B
authors.initials: B
authors.lastname: Jacobsson
authors.affiliation: Department of Genes and Environment, Norwegian Institute of Public Health, Oslo, Norway.|Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway.
authors.forename: H K
authors.initials: HK
authors.lastname: Gjessing
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D047109:Fetal Development; D005865:Gestational Age; D057238:Growth Charts; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D011446:Prospective Studies; D011631:Pubic Symphysis / Q000000981:diagnostic imaging*; D012372:ROC Curve; D012042:Registries; D012307:Risk Factors; D013548:Sweden; D016216:Ultrasonography, Prenatal; D055815:Young Adult
keywords: Antenatal care; fetal growth restriction; low-risk pregnancy; population-based reference curve; pregnancy surveillance; small-for-gestational-age; symphysis-fundus height