Gzernichow P

Robert Debre Hospital, Paris, France


Babies with a birth weigh or birth length below a particular percentile are describe as small for gestational age (SGA).The definition of SGA infants depends on the accurate determination of gestational age (GA) and on the precision in the evaluation of weight measurement at birth. Indeed different criteria have been used for auxological definition of SGA. In most publications the definition of being SGA relies on birth weight alone using different cut-off levels such as 10,5,3 centile for GA or below 2 SD below the mean for GA. Birth length has been used less frequently for the diagnosis of SGA. Ponderal index as also been used to describe the relation between weight and length: in í░symetricí▒ SGA both weight and length are reduced and in í░asymetricí▒ cases weight is reduced more than length.


It is now accepted that growth retardation is a consequence of decreased fetal production of IGF1 and insulin. When adequate nutrition is given after delivery, endocrine parameters are quickly normalized and plasma concentration of both hormone are normal by 3 month of life.


Several studies are available on the consequences being SGA on postnatal growth and final height. Due to improvement in the methods used to take care of early postnatal nutrition results varies in the survey conducted in the last 30 year. In brief the outcome has been greatly improved.


Catch up growth occurs in most in not all children born SGA but the duration and importance of the catch up vary from on child to another. In the most recent studies in Europe this catch up is insufficient and close to 10% of cases will remain-2SD below the mean for height at the age of 2 years. Prematurity and severity of growth retardation are strong predictors of short stature at this age. After 2 years of age catch up is infrequent and small stature will persist throughout childhood and adolescence, and will influence strongly final height.