Early puberty: Rapid progression and reduced final height in girls with low birth weight

Objective. To assess whether, in girls with early onset of puberty, low bir th weight is a risk factor for rapid progression to menarche and for short adult stature. Design. Longitudinal clinical assessment of 54 Catalan (Northern Spanish) g irls followed from early onset of puberty (onset of breast development betw een 8.0 and 9.0 years of age) to final height. The timing of menarche and t he final height were analyzed a posteriori according to birth weight the cu toff level between normal and low birth weight subgroups being -1.5 standar d deviation (SD; similar to2.7 kg at term birth). Results. Normal and low birth weight girls had similar target heights and c haracteristics at diagnosis of early puberty. However, menarche occurred on average 1.6 years earlier in low versus normal birth weight girls (11.3 +/ - .3 years vs 12.9 +/- .2 years), and final height was >5 cm shorter in low birth weight girls (parental adjusted height SD: -.6 +/- .2 cm vs .3 +/- . 2 cm). Conclusion. The timing of menarche and the level of final height in Catalan girls with early onset of puberty was found to depend on prenatal growth. Girls with normal birth weight tend to progress slowly through puberty with a normal timing of menarche and normal final height. In contrast, girls wi th low birth weight tend to progress relatively rapidly to an early menarch e and to a reduced final height. If these findings are confirmed in other e thnic and/or larger groups, then a subgroup has been identified that will m ost likely benefit from any therapeutic intervention aiming at a delay of p ubertal development and/or an increase of final height.