Post menarcheal growth patterns in a contemporary cohort of Latino girls.

Introduction: Menarche is the last stage of pubertal development, which coincides with the completion of longitudinal growth. As a consequence of the lack of national and up-to-date data related to post-menarcheal (PM) growth, the aim of our work was to evaluate post menarcheal growth in a group of contemporary healthy Chilean girls followed, prospectively, until 4 years post-menarche.

Methods: This study was nested within the GOCS cohort, in a prospective fashion. The girls were followed yearly after menarche for at least four years. We modeled each girl growth using a Super Imposition by Translation and Rotation (SITAR) model.

Results: A total of 534 girls were evaluated prospectively, 399 girls had height measured two years after menarche, 421 after three years, and 364 of 534 had height measured at four year post menarche. Expected height gained PM, in the complete study group was 6.6 ± 2.5 cm. We observed that the largest gain in height occurred after the first year PM (3.8 1.5 cm). According to the age of menarche, the group with earlier menarche (< 11 years old ) had a greater height gain in cm after four years PM ( 8.2± 3.2 cm ) and the smallest gain was among girls with menarche at an age older than 13 yr (4.4±1.6) ( p<0.001). Age at menarche was significantly associated with all post menarche growth patterns (size, timing and intensity), indicating that girls with older age at menarche grew taller, later and slower than girls with younger age at menarche. Adjusting PM growth pattern by BMI maintained all these association. Applying the SITAR model specifically , girls experiencing menarche after the age of 13 years exhibited slower growth , occurring slightly earlier and with less intensity when adjusted by BMI at menarche .

Conclusion: In a national and updated dataset we observed that girls grew until 4 years post menarche an average of 6.6 ± 2.5 cm., with greatest gain occurring in the first year PM , (3.8 ± 1.5 cm). Age at menarche was associated with menarche growth patterns.