There is a paucity of data on whether being born small for gestational age(SGA) has a long-term detrimental effect. Our aim was to assess the late cognitive outcome of small compared with appropriate for gestational age (AGA) infants. SGA was defined for each gestational age as birth weight below the 10th percentile on a growth curve determined for our entire study population. We performed a population based analysis of 10,956 consecutive singleton infants born between November 1974 and February 1976. Perinatal data were obtained from the computerized records of the Jerusalem Study on Oral Contraceptive Use. Intelligence test scores at age 17 were available from military draft records. A multiple linear regression analysis was used to control for the effects of the studied independent variables. These included maternal body mass index (BMI; kg/m2), weight gain, hypertension and diabetes during pregnancy, birth asphyxia, instrumental or cesarean delivery, birth order, parental educational attainment, ethnic origin and social status, and the subjects' BMI and height at 17 years of age. The adjusted Mean±SEM intelligence test scores at 17 years of age by sex, gestational age, and size at birth are given in the table.

Table 1 (Statistical comparison of SGA to AGA: aNon-Significant;b p<0.002; cp<0.01.)

A logistic regression showed no significantly increased risk for low intelligence scores (<85) in SGA vs. AGA term infants, odds ratios 1.46(95% C.I. 0.95-2.26) for males and 1.26 (0.82-1.93) for females. We conclude that term SGA infants have a minimally, but statistically significant, lower intelligence test scores in late adolescence compared with term AGA infants, even after correction for the effect of multiple demographic and clinical confounding factors.