title: Charts for fetal age assessment based on fetal sonographic biometry in a population from Cali, Colombia.
abstract: OBJECTIVE
  To create reference charts for fetal age assessment based on fetal sonographic biometry in a population of pregnant women living in the third largest city in Colombia and compare them with charts included in ultrasound machines.
  
  
  METHODS
  The study data were obtained from women with a single pregnancy and confirmed gestational age between 12 and 40 completed weeks. All women were recruited specifically for the study, and every fetus was measured only once for biparietal diameter, head circumference, abdominal circumference, and femur length. Polynomial regression models for gestational age as a function of each fetal measurement were fitted to estimate the mean and standard deviation. Percentile curves of gestational age were constructed for each fetal measurement using these regression models.
  
  
  RESULTS
  Biparietal diameter, head circumference, abdominal circumference, and femur length were measured in 792 fetuses. Tables and charts of gestational age were derived for each fetal parameter. A cubic polynomial model was the best-fitted regression model to describe the relationships between gestational age and each fetal measurement. The standard deviation was estimated by simple linear regression as a function of each fetal measurement. Comparison of our gestational age mean z scores with those calculated by reference equations showed statistically significant differences (P < .01).
  
  
  CONCLUSIONS
  We present a set of reference charts, tables, and formulas for fetal age assessment based on fetal sonographic biometry. The results support the recommendation that these charts and tables could be more appropriate for assessing fetal age in Colombian populations than those currently included in the software of ultrasound machines.
authors.affiliation: Children's Heart Center Nevada, 3006 S Maryland Pkwy, Suite 690, Las Vegas, NV 89109 USA. hurescan@gmail.com.
authors.forename: Freddy
authors.initials: F
authors.lastname: Briceño
authors.forename: Humberto
authors.initials: H
authors.lastname: Restrepo
authors.forename: Ricardo
authors.initials: R
authors.lastname: Paredes
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Cifuentes
mesh_terms: D000365:Age Determination by Skeleton / Q000379:methods / Q000706:statistics & numerical data*; D000465:Algorithms; D001699:Biometry / Q000379:methods*; D049628:Body Size; D003105:Colombia / Q000453:epidemiology; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging* / Q000196:embryology*; D005865:Gestational Age; D006801:Humans; D008297:Male; D011247:Pregnancy; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D016216:Ultrasonography, Prenatal / Q000379:methods / Q000706:statistics & numerical data*
keywords: abdominal circumference; biparietal diameter; femur length; fetal age assessment; head circumference; obstetric sonography