全球研究表明女孩月经初潮的平均年龄正在逐年下降1。据统计，从1977年的平均10.5岁下降到2013年的9.6岁，每十年平均提前约三个月1。在美国，这一趋势同样明显，1950-1969年出生者的平均初潮年龄为12.5岁，而2000-2005年出生者则下降至11.9岁1。澳大利亚女孩的平均初潮年龄约为12.9岁，正常范围在9-15岁之间1。
月经初潮时间受多种因素影响，其中遗传因素占重要地位。约400个基因和遗传标记与初潮时间相关，遗传因素约占时间变异的25-50%1。体重、饮食、运动和环境化学物等也会产生影响1。然而，科学研究表明父母无法通过特定的饮食或运动方案来安全延迟正常青春期发育1。值得注意的是，约3%的儿童在8岁前出现发育迹象，但其中仅约0.2%患有需要治疗的医学问题1。
Research demonstrates that the average age of menarche has declined significantly across the globe over recent decades.1 In the United States, the mean age dropped from 12.5 years among those born between 1950 and 1969 to 11.9 years for those born between 2000 and 2005.1 International data reveal an even more pronounced trend, with global average menarche age falling from approximately 10.5 years in 1977 to 9.6 years by 2013, representing a decline of roughly three months per decade.1 Australia has documented a mean menarche age of approximately 12.9 years, with the normal developmental range extending from 9 to 15 years.1
The biological factors influencing when girls begin menstruating are complex and multifaceted. Approximately 400 genes and genetic markers are associated with menarche timing, with genetic factors accounting for 25 to 50 percent of the variation in onset age.1 Environmental and physiological elements including body weight, dietary patterns, physical activity levels, and exposure to environmental chemicals also play significant roles.1 However, parents seeking to delay normal puberty through targeted dietary or exercise interventions should understand that no safe, evidence-based approach exists to accomplish this goal.1 Among children exhibiting developmental signs, only about 3 percent show such signs before age 8, and merely 0.2 percent have underlying medical conditions requiring treatment.1
评论
还没有评论，欢迎留下第一条。