Longitudinal study of the pubertal growth spurt in children born small for gestational age without postnatal catch-up growth

Most children born small for gestational age (SGA) experience extensive catch-up growth during the first months of life (87%) and by the age of 2 years only 13% are below -2 SDS for height. The long-term outcome, including pubertal growth spurt, of the subset of children born SGA without postnatal catch-up (SGAWPC) has been evaluated in very few surveys, and in none of them was the landmarks of puberty well described. Thus, a longitudinal study was conducted in these children throughout puberty since this is the only reliable way to accurately evaluate the pubertal growth spurt. In an observational, retrospective and multicenter collaborative study, from an initial group of 553 SGA children, a subset of 15 boys (BW = 2,070 +/- 379.6 g) and 16 girls (BW = 2,244 +/- 331.1 g) SGAWPC whose data were recorded regularly during puberty were selected. Growth standards for growth and maturity during puberty were Tanner and Whitehouse and Spanish Hernandez and Sobradillo charts. In pubertal growth spurt, 'take-off' occurred later than in the reference populations with a height SDS deficiency of -2.3 and -2.2 for boys and -2.0 and -1.9 for girls, compared with Spanish and Tanner references, respectively. Peak height velocity was normal in chronology and intensity, but the total pubertal gain was smaller. However, considering their growth from the same chronological age at which the reference populations took off until adulthood, the total gain was not significantly different in the three cohorts (32.5 +/- 5.4 cm vs 30.9 +/- 4.4 in boys, and 23.3 +/- 4.1 vs 25.7 +/- 5.4 cm in girls - Spanish reference - and 27.2 +/- 6.3 vs 27.6 +/- 3.5 cm in boys - Tanner charts), except in the case of girls (21.1 +/- 3.9 vs 25.3 +/- 4.1 cm, p <0.005 - Tanner charts). Adult height was significantly reduced (161.9 +/- 3.9 cm in males and 147.0 +/- 2.6 cm in females). Therefore, although the pubertal growth was smaller in these children, puberty probably did not modify their short final height.