Glossary

"Asphyxia neonatorum: Pathological changes caused by lack of oxygen in respired air, resulting in hypoxia and hypercapnia in the infant during labour, delivery, or the immediate postnatal period."(Anderson, 2003)  A variety of signs such as Apgar scores, cord artery pH, presence of one or more organ failure after birth or evidence of ischemic encephalopathy have been used to diagnose asphyxia neonatorum.

Assignment of gestational age in the Perinatal Follow Up Program:The assignment of gestational age is based upon computing the expected date of delivery from one of the following seven criteria: 1) date of conception 2) maternal dates, 3) early ultrasound, or 4) clinical assessment of the baby.  The following algorithm is used to determine this expected date of delivery:

1. Use date of conception if:
a. The date of fertilization by in vitro fertilization is known; or
b. The mother has been instructed in the use of maternal signs of ovulation by a fertility clinic

2. Use maternal dates if:
a. no other estimate is available; or
b. maternal dates are supported by an ultrasound within 10 days (irrespective of how certain the dates are) and there are no other estimates of gestational age

3. Use ultrasound if:
a. maternal dates are unknown; or
b. the maternal dates are known and they are > 10  days discrepant  with the ultrasound and there are no other estimates of gestational age

Use clinical assessment of the baby there are no other estimates available

Auditory impairment: Lack of or significant deficiency of the sense of hearing such that the unaided best ear.  The specific definition varies, however, the WHO tends to define deafness as worse than 95 decibel hearing in the best ear, while significant hearing impairment (requiring some assistance) is in the region of 25 decibels in the best ear.

"Cerebral Palsy  (CP): Describes a group of disorders of the development of movement and posture, causing activity limitation, that are attributed to non progressive disturbances that occurred in the developing fetal or infant brain. The motor disorders of cerebral palsy are often accompanied by disturbances of sensation, cognition, communication, perception, and/or behaviour, and/or by a seizure disorder."(Bax et al., 2005)  For the Perinatal Follow Up Program the following criteria define the severity of CP:

Severe:  those infants who are nonambulatory or never likely to be ambulatory and would fall into level IV or V on the gross motor functional classification system(Palisano et al., 1997)

Moderate:   those infants who are ambulatory but with a great deal of difficulty (e.g. requiring a walker or gait that interferes in normal ambulation.  These infants may also have some difficulty with fine motor control.  They would fall into level II or II on the gross motor functional classification system(Palisano et al., 1997)

Mild:  those infants who have minimal gait disturbances and minimal or no upper limb involvement and would fall into level I on the gross motor functional classification system(Palisano et al., 1997)

Cognitive impairment: "Impairment of the operation of the mind by which one becomes aware of objects of thought or perception; it includes all aspects of perceiving, thinking, and remembering." (Anderson, 2003)

Correction for prematurity: The age of the child using mother's best estimate of the expected date of delivery.

"Epilepsy (seizure): Is any of a group of syndromes characterized by paroxysmal transient disturbances of the brain function that may be manifested as episodic impairment or loss of consciousness, abnormal motor phenomenon, psychic or sensory disturbances, or perturbation of the autonomic nervous system.  A single episode is called a seizure."(Anderson, 2003)

Extremely low birth weight infant: Infants born with weights < 1000 grams.

"Failure to thrive (FTT): is diagnosed in an infant or child whose physical growth is significantly less than that of his or her peers, and it is often associated with poor developmental and cognitive functioning. Although there is no clear consensus definition, FTT usually refers to growth below the 3rd or 5th percentile or a change in growth that has crossed two major growth percentiles (i.e., from above the 75th percentile to below the 25th) in a short time."(Behrman, Kliegman, & Jenson, 2004)

High risk infants:  Any risk factor that places infants at high risk for adverse outcome.  For example, very low birth weight infants are at high risk for cerebral palsy and other neurodevelopmental disabilities.

Hydrocephalus: Dilatation of the cerebral ventricles, sometimes known in the lay literature as "water on the brain".

Hypertension: Elevated arterial blood pressure.  Generally measured with either a syphgmomenometer or with the oscillatometric technique.  For children, tables of abnormal blood pressure can be found on the National Institute of Health website: http://www.nhlbi.nih.gov/guidelines/hypertension/child_tbl.htm

Hypoglycemia: "an abnormally diminished concentration of glucose in the blood....."(Anderson, 2003).  In preterm newborns this is generally considered a blood sugar < 2 mmol/L.

"Hypoxic ischemic encephalopathy: a degenerative brain disease resulting from asphyxia neonatorum."(Anderson, 2003)  It is frequently characterized by lethargy, feeding difficulties, seizures and alteration in consciousness.  In the severe end of the spectrum hypoxic ischemic encephalopathy may be associated with neonatal death or long term disabling conditions such as cerebral palsy, psychomotor retardation or impairments of special senses.

Language delay: Any delay in the normal acquisition receptive, expressive or combined language milestones.

"Meningitis:  is an inflammation of the meninges, usually by either a bacterium (bacterial meningitis) or a virus (viral meningitis).  The meninges are the three membranes that envelop the brain and spinal cord: the dura matter, pia matter and arachnoid."(Anderson, 2003)

Perinatal: Perinatal refers to the period before birth (usually from 20th week of pregnancy or more) to some time after birth (usually 7 or 28 days).

Perinatal Mortality Rate (PMR): The ratio of deaths in the perinatal period (stillbirths plus neonatal deaths) divided by all births.  Thus the PMR is as follows:

PMR =
stillbirths + neonatal deaths

stillbirths + all live births

It should be noted that neonatal mortality is sometimes defined as death up to 7 days of age and at other times death up to 28 days of age.

Periventricular leukomalacia: "ecrosis of the white matter of the brain adjacent to the lateral ventricles, seen in the neonatal period, especially in premature newborns, and manifested by chalky, yellowish white plaques in the white matter, with proliferation of astrocytes and microglia; cyst formation may lead to multicytics encephalopathy."(Anderson, 2003)


Population based: A complete (100%) cohort of individuals drawn from a geographic region.

Sensory impairments: Impairment of special senses (hearing or vision).

Small for gestational age: Defined many ways, however, the key elements of the definition usually include a birth weight below a stated percentile or number of standard deviations on the birth weight for gestational age intrauterine growth curve.  For example, infants could be said to be small for gestational age if their birth weight was less then the third percentile on the growth curve.  Synonyms include:  small for dates, light for dates, intrauterine growth restriction, intrauterine growth retardation.

very preterm infant: For the Perinatal Follow Up Program, infants < 31 weeks gestational age

very low birth weight infant: Infants born with weights < 1500 grams.

Visual impairment:  Lack of or significant deficiency of the sense of vision.  Generally blindness is considered as vision no better than 20/200 in the best eye.

 

Reference List

Anderson, D. M. (2003). Dorland's Illustrated Medical Dictionary. (30 ed.) W.B. Saunders Company.

Bax, M., Goldstein, M., Rosenbaum, P., Leviton, A., Paneth, N., Dan, B. et al. (2005). Proposed definition and classification of cerebral palsy, April 2005. Dev Med Child Neurol, 47, 571 576.

Behrman, R. E., Kliegman, R. M., & Jenson, H. B. (2004). Nelson Textbook of Pediatrics.

Palisano, R., Rosenbaum, P., Walter, S., Russell, D., Wood, E., & Galuppi, B. (1997). Development and reliability of a system to classify gross motor function in children with cerebral palsy. Dev.Med.Child Neurol., 39, 214 223.                                                                   

 

                                     

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