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Adolescent childbirth is associated with worse physical function over the long-term. Differential loss of muscle strength during pregnancy and postpartum for adolescents compared to adults may be one explanation for this, but research examining these differences is lacking. The objective of this study as to assess hand grip strength and hip adduction muscle strength in adolescents and adults during pregnancy and postpartum. A prospective cohort study was carried out with adolescent (13 to 18 years) and adult (23 to 28 years) primigravid women. Assessments were performed at three timepoints: before the 16th gestational week, during the third trimester, and between the fourth and sixth week postpartum. Hand grip strength (continuous and muscle weakness if ≤ 20.67 kgf) and hip adductor measures (continuous and muscle weakness if ≤ 13.8 kgf) were assessed using dynamometry. Generalized estimating equations modelled longitudinal relationships between muscle weakness and age group. More adolescents had hip adductor weakness than adults in the third trimester of pregnancy (62.5% vs. 31.8%, p < 0.005), which was corroborated by the longitudinal analyses. For all women, there were higher odds of hip adductor weakness in the third trimester (OR = 4.35; p< 0.001) and postpartum (OR = 9.45; p < 0.001) compared to the 16th gestational week. No significant difference in HGS was observed between age groups or across the different timepoints. The higher proportion of hip adductor weakness among adolescents may indicate a need for resistance training during and after pregnancy and physical therapy if weakness or injury is noted.青少年分娩与长期较差的躯体功能存在关联。与成年女性相比，青少年群体在孕期及产后的肌肉力量流失存在差异，这或许是上述关联的潜在成因之一，但目前针对此类差异的相关研究仍较为匮乏。本研究旨在评估青少年与成年女性在孕期及产后的手握力量与髋内收肌力量水平。本研究针对初产妇开展前瞻性队列研究，其中青少年组年龄为13至18岁，成年组为23至28岁。研究分别在三个时间点开展评估：妊娠16周前、妊娠晚期（第三孕期）以及产后4至6周。采用肌力测试仪评估手握力量（Hand Grip Strength，简称HGS，以连续数值记录，当力量≤20.67千克力时判定为肌肉无力）与髋内收肌力量（以连续数值记录，当力量≤13.8千克力时判定为肌肉无力）。采用广义估计方程（Generalized Estimating Equations）建模分析肌肉无力与年龄组之间的纵向关联。妊娠晚期，青少年群体的髋内收肌无力发生率显著高于成年女性（62.5% vs. 31.8%，p<0.005），该结果得到纵向分析的验证。相较于妊娠16周时，所有受试女性在妊娠晚期（优势比OR=4.35；p<0.001）及产后（OR=9.45；p<0.001）出现髋内收肌无力的比值比更高。不同年龄组间以及各时间点的手握力量（HGS）均未出现显著差异。青少年群体中髋内收肌无力的占比更高，这提示需在孕期及产后为该群体提供抗阻训练，若出现肌肉无力或损伤则需辅以物理治疗。