STUDY QUESTION Is age at menarche associated with fecundability? SUMMARY ANSWER Both early (<11 years) and late (>15 years) menarche is associated with decreased fecundability. WHAT IS KNOWN ALREADY Previous studies on age at menarche and fecundability have been inconclusive. Women with early or late menarche are at increased risks of gynaecological and autoimmune diseases that may affect their ability to conceive. STUDY DESIGN, SIZE, DURATION We conducted a retrospective cohort study including 67 613 pregnant women, participating in the Norwegian Mother, Father and Child Cohort Study between 1999 and 2008, with self-reported information on age at menarche and time to pregnancy. We included planned pregnancies that were conceived either naturally or with the help of assisted reproductive technologies. PARTICIPANTS/MATERIALS, SETTING, METHODS We calculated fecundability ratios (FRs) with 95% CIs representing the cycle-specific probability of conception by categories of age at menarche. FRs were adjusted for participants’ pre-pregnancy body mass index, highest completed or ongoing education level, and age at initiation of trying to conceive. MAIN RESULTS AND THE ROLE OF CHANCE We observed a 7% lower probability of conceiving during any given menstrual cycle up to 12 cycles in women with early or late menarche. Among women with menarche >15 years, the adjusted FR was 0.93 (95% CI: 0.90–0.97), and among women with menarche <11 years, the adjusted FR was 0.93 (95% CI: 0.89–0.99), when compared to women with menarche between 12 and 14 years. LIMITATIONS, REASONS FOR CAUTION The study-population consisted of women pregnant in their second trimester, excluding those with persistent infertility. Recall of age at menarche and time to pregnancy may be inaccurate. WIDER IMPLICATIONS OF THE FINDINGS Both early (<11 years) and late (>15 years) menarche was associated with decreased fecundability. Women experiencing early menarche or late menarche may be counselled accordingly. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by the Norwegian Institute of Public Health, Oslo, Norway, and by Telemark Hospital Trust, Porsgrunn, Norway and was partly supported by the Research Council of Norway through its centres of excellence funding scheme (project number 262700) and the Research Council of Norway (project no. 320656). The project was co-funded by the European Union (ERC, BIOSFER, 101071773). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European Union or the European Research Council. Neither the European Union nor the granting authority can be held responsible for them. M.C.M. has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement no. 947684). The authors report no competing interests. TRIAL REGISTRATION NUMBER N/A.

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挪威母亲、父亲和儿童队列研究显示，初潮提前或推迟与生育力降低有关

研究问题 初潮年龄与生育能力有关吗？摘要答案 初潮早（<11 岁）和晚（>15 岁）都与生育力下降有关。已知的信息 之前关于初潮年龄和生育能力的研究尚无定论。初潮早或晚的女性患妇科疾病和自身免疫性疾病的风险增加，这些疾病可能会影响她们的受孕能力。研究设计、规模、持续时间 我们进行了一项回顾性队列研究，纳入了 1999 年至 2008 年间参加挪威母亲、父亲和儿童队列研究的 67 613 名孕妇，并自我报告了初潮年龄和怀孕时间的信息。我们纳入了自然受孕或辅助生殖技术帮助下的计划怀孕。参与者/材料、环境、方法 我们计算了受孕率 (FR)，其中 95% CI 代表了按初潮年龄分类的特定周期受孕概率。 FRs根据参与者的孕前体重指数、最高完成或正在进行的教育水平以及开始尝试怀孕的年龄进行了调整。主要结果和机会的作用 我们观察到，初潮早或晚的女性在任何给定的月经周期（最多 12 个周期）内受孕的概率降低 7%。在初潮> 15年的女性中，调整后的FR为0.93（95％CI：0.90-0.97），在初潮<11年的女性中，调整后的FR为0.93（95％CI：0.89-0.99），当与 12 至 14 岁初潮的女性相比。局限性和注意事项 研究人群由妊娠中期的女性组成，不包括持续不孕的女性。回忆初潮年龄和怀孕时间可能不准确。该发现的更广泛意义初潮早（<11岁）和晚（>15岁）都与生育能力下降相关。初潮早或初潮晚的女性可能会得到相应的咨询。研究经费/竞争利益 这项研究由挪威奥斯陆挪威公共卫生研究所和挪威波尔斯格伦泰勒马克医院信托基金资助，并得到挪威研究委员会通过其卓越中心资助计划的部分支持（项目号 262700）和挪威研究理事会（项目号 320656）。该项目由欧盟（ERC，BIOSFER，101071773）共同资助。然而，所表达的观点和意见仅代表作者的观点和意见，并不一定反映欧盟或欧洲研究理事会的观点和意见。欧盟和授权机构都不能对此承担责任。 MCM 已根据欧盟 Horizo​​n 2020 研究和创新计划获得了欧洲研究理事会 (ERC) 的资助（资助协议编号 947684）。作者报告没有竞争利益。试用注册号 不适用。