Prospective longitudinal clinical study of 30 twin pairs at birth, prepubertally at ages 2.1, 4.0, 10.0 years, and mid-/postpubertally at age 14.6 years; 14 pairs were concordant (birthweight difference <1 SDS), 16 discordant (birthweight difference >1 SDS).
In 19/30 (63%) pairs, the initially smaller twin started pubertal maturation before the co-twin. In 7/8 (88%) female discordant twin pairs, the initially smaller twin experienced menarche first. Among discordant pairs, highly significant intra-twin differences for height SDS were observed up to 10 years of age, with a further decline between ages 10.0 and 14.6 years. At 10.0 years of age, significant intra-twin differences in mean dehydroepiandrostenedione sulfate were observed in all twin pairs (870.3 vs 1054 ng/mL in the smaller twin,
Birthweight has an impact on growth and pubertal maturation. The already decreased height in some low birthweight infants may be further impacted by an early start and fast progression of puberty. The high intra-twin correlation coefficients in our study suggest that puberty and sexual steroids are genetically determined. However, the observed adrenal androgen hypersecretion of the smaller twin during late childhood could have effected pubertal maturation and further decreased near final height.