Jenni Gårdstedt-Berghog ^1,2 Aimon Niklasson ³ Agneta Sjöberg ⁴ A. Stefan Aronson ^5,6 Aldina Pivodic ^7,8 Andreas F. Nierop ^2,9 Kerstin Albertsson-wikland ² Anton Holmgren ^10,11,6*

• ¹ Department of Gynecology and Obstetrics, Halland Hospital Halmstad, Halmstad, Sweden
• ² Department of Physiology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
• ³ Gothenburg Pediatric Growth Research Center (GP-GRC), Department of Pediatrics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
• ⁴ Department of Nutrition and Sports Science, Faculty of Education, University of Gothenburg, Gothenburg, Sweden
• ⁵ Department of Physiology/Endocrinology, Institute of Neuroscience and Physiology, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
• ⁶ Gothenburg Pediatric Growth Research Center, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
• ⁷ APNC Sweden, Gothenburg, Sweden
• ⁸ Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Västergötland, Sweden
• ⁹ Muvara bv, Multivariable Analysis of Research Data, Leiderdorp, Netherlands
• ¹⁰ Department of Pediatrics, Halland Hospital, Halmstad, Sweden
• ¹¹ Department of Research and Development, Region Halland, Halmstad, Sweden

Objectives: To explore timing of menarche, post-menarcheal growth, and to investigate the impact of various variables on menarcheal age, post-menarcheal and pubertal growth.Study Design: This longitudinal community population-based study analyzed pubertal growth and menarcheal age in 793 healthy term-born Swedish girls, a subset of the GrowUp1990Gothenburg cohort. Timing of menarche and post-menarcheal growth were related to variables from the QEPS (quadratic-exponential-pubertal-stop) growth model, birth characteristics, and parental height. Multivariable models were constructed for clinical milestones; at birth, age 7 years, pubertal growth onset and mid-puberty.Results: Menarche aligned with 71.6% (18.8) of the QEPS-model's specific pubertal growth function, at a mean age of 13.0 (1.3) years, ranging from 8.2 to 17.2 years. Post-menarcheal growth averaged 8.0 (4.9) cm, varying widely from 0.2 to 31.1 cm, decreasing with later menarche. Significant factors associated with menarcheal age included height at 7 years, childhood body-mass index (BMI), parental height, and QEPS-derived pubertal growth variables. Multivariable models demonstrated increasing explanatory power for each milestone, explaining 1% of the variance in menarcheal age at birth, 8% at age 7 years, 44% at onset of pubertal growth and 45% at mid-puberty.This study underscores the strong link between pubertal growth and age at menarche. Data available at start of puberty explain 44% of the variation in menarcheal age, apparent on average 3.2 years before menarche. Additionally, the study shows a previously seldom noticed wide variation in post-menarcheal height gain from 0.2 to 31.1 cm.