Appropriate for gestational age (AGA):Infants whose birthweights are as expected for their gestational age; 10th - 90th percentile is often used.
Arnold Chiari malformation: a malformation that can accompany myelomeningocele and other neural tube disorders where the cerebellum and medulla oblongata protrude into the spinal canal.
Asymmetric IUGR: IUGR that has resulted in weight and length measurements that are less than expected for gestational age, but a "normal" head circumference.
Bronchopulmonary dysplasia (BPD): a chronic lung disorder that is most common among children who were born prematurely, with low birthweights, and who received prolonged mechanical ventilation.
Catch-up growth: a term used to describe a rate of growth that is faster than expected. For infants born with low birthweights or small for gestational age, catch-up growth can describe gains in weight or length where the measurement reaches the 5th percentile for age (when it had previously been below the 5th percentile). In other instances, catch-up growth refers to weight and/or height gains when a child who has experienced stunted growth receives adequate energy and protein.
Cerebral palsy: a motor nerve disorder caused by injury to the central nervous system; symptoms depend on the area of the brain involved and the severity of the damage.
Contractures: static muscle shortening resulting from tonic spasm or fibrosis; frequently seen in individuals with cerebral palsy.
Cornelia deLange syndrome: a congenital syndrome characterized by short stature, microcephaly, delayed development and mental retardation, a number of distinct facial features, and upper limb anomalies; also referred to as deLange syndrome and Brachmann-deLange syndrome.
Corrected age: the age of an infant from birth, less the number of weeks premature.
Early intervention services: established by Part H of P.L. 97-457 of 1986 (now Part C of the IDEA of 1997); community-based therapeutic and educational services for infants and children under 3 years of age with developmental delays.
Encephalopathy: any degenerative disease of the brain.
Gastroesophageal reflux (GER): regurgitation of the contents of the stomach into the esophagus, where they can be aspirated; often results from a failure of the esophageal sphincter to close.
Gestational age: the age of a fetus or newborn, usually stated in weeks from the first day of the mother's last menstrual period.
Hypotonia: diminished muscle tone.
Infant Health and Development Program (IHDP): a national collaborative clinical study of low birthweight preterm infants.
Intrauterine growth retardation (IUGR): development of the fetus that is delayed related to gestational age.
Intraventricular hemorrhage: bleeding into or near the ventricles within the brain; severity ranges from Grade I to Grade IV.
Low birth weight: infants weighing between 1500 and 2500 g at birth.
Myelomeningocele: a congenital defect that results in a hernia (containing the spinal cord, the meninges and cerebral spinal fluid) along the spinal column, also called spina bifida.
Neural tube defects: any defect of the brain and spinal cord that is caused by failure of the neural tube to close during growth during pregnancy.
Prader-Willi syndrome: a genetic disorder marked by hypotonia, short stature, hyperphagia and cognitive impairment.
Rett syndrome: an X-linked disorder marked by progressive neurological deterioration, seizures, and microcephaly.
Scoliosis: a sideways curve of the spine resulting in an S shape of the back.
Small for gestational age: infants whose birthweights are less than expected for their gestational age; <10th percentile is often used.
Symmetric IUGR: IUGR that has resulted in weight, length, and head circumference measurements that are less than expected for gestational age.
Triceps skinfold measures: measurement of the skin and subcutaneous fat layer around the triceps muscle, used with arm circumference measurement to estimate fat and muscle stores.
Turner syndrome: a disorder in females marked by the absence of one X chromosome, typically characterized by ovarian failure, genital tissue defects, cardiac problems, and short stature.
Trisomy 21: a genetic disorder in which an individual has an extra 21st chromosome, typically characterized by low muscle tone, cardiac problems, GI malformations, and a distinct facial appearance; also called Down syndrome.
Very low birth weight: infants weighing less than 1500 g at birth.