Neonatal anthropometric charts: what they are, what they are not
- 1Cattedra di Neonatologia, Dipartimento di Scienze Pediatriche, Università di Torino, Turin, Italy
- 2Istituto di Statistica Medica e Biometria, Università di Milano, Milan, Italy
- 3Dipartimento di Scienze Ginecologiche, Perinatologia e Puericultura, Università La Sapienza, Rome, Italy
- Correspondence to:
M De Curtis
Dipartimento di Scienze Ginecologiche, Policlinico Umberto I, Via del Policlinico 155, 00161 Rome, Italy;
- Accepted 12 June 2006
Over 40 years have elapsed since Lubchenco et al1 proposed an anthropometric classification of neonates based on the so-called intrauterine growth charts—that is, birth weight-for-gestational age charts.
ARE NEONATAL ANTHROPOMETRIC CHARTS INTRAUTERINE GROWTH CHARTS?
The use of charts, such as those given by Lubchenco et al,1 based on the distribution of measurements taken on neonates with different gestational age, should be restricted to the auxological assessment of babies at birth. These charts, now called neonatal anthropometric charts, must not be confused with the intrauterine growth charts, which are a tool for monitoring fetal growth, based on ultrasound measurements of anthropometric traits during pregnancy: preterm births are abnormal events and preterm neonates cannot be equated to fetuses of the same gestational age who will be born at term.2 When fetal growth studies are longitudinal, both distance and velocity intrauterine growth charts may be traced.3,4 Strictly speaking, only charts derived from longitudinal studies should be called growth charts, growth being a process extended over time.
DOES “SMALL-FOR-GESTATIONAL AGE” MEAN “INTRAUTERINE GROWTH RESTRICTED”?
The terms SGA and intrauterine growth restriction (IUGR) are often used as synonyms, although they reflect two different concepts. SGA refers to a statistical definition, based on an auxological cross-sectional evaluation (prenatal or neonatal), and denotes a fetus or a neonate whose anthropometric variables (usually weight) are lower than a given threshold value computed on a set of infants having the same gestational age. SGA includes infants who have not achieved their own growth potential, because of maternal, uterine, placental and fetal factors,5,6 as well as small but otherwise healthy infants. IUGR refers to a clinical and functional condition and denotes fetuses unable to achieve their own growth potential: a fetus with IUGR would have been larger, without adverse environmental or genetic factors affecting growth. Such a condition can be assessed by ultrasonography during pregnancy by …