EFFECTS OF BIRTHWEIGHT AND GESTATIONAL AGE UPON GROWTH IN BRAZILIAN INFANTS: A LONGITUDINAL STUDY

A sample of 262 Brazilian infants of working class families born at the Brazilia Teaching Hospital between April 1975 and November 1978 were followed at 4 8 12 and 18 month intervals to determine the effects of intrauterine growth and gestational age upon weight height and head circumference. Intrauterine growth was calculated from the womans last menstrual period. Infants were considered born at term if their gestational age was 37 weeks. They were classified into term premature-appropriate-for-dates and small-for-dates categories. Parents were asked questions about income educational level occupation type of dwelling home ownership. This data was used as a covariate. At 4 months all infants differed sharply in weight height and head circumference. At 8 months premature-appropriate-for-dates surpassed the term group in weight. At 18 months intrauterine growth continued to be more important than gestational age to the prediction of weight. In terms of height at 4 months gestational age is more important than intrauterine growth but at approximately 15 months the small-for-dates begin to surpass the term infants. At 4 months the premature appropriate for dates had smaller head sizes than children born at term but at 18 months they surpassed the term group in head circumference. After 4 months maternal height and economic status have a bearing on both the childs height and head circumference. It is concluded that intrauterine growth based upon birthweight for gestational age is predictive of weight height and head circumference up to 18 months.