尽管有证据显示生殖因素与子宫内膜癌风险存在相关性，但前瞻性研究主要是在非亚洲国家进行的。为了评估生殖因素（如分娩次数、月经初潮或绝经时期）与子宫内膜癌风险之间的关联，本队列研究使用亚洲队列联盟在1963年至2014年间进行的13项前瞻性队列研究的合并个体数据。参与者均为亚洲妇女，数据分析时间为2019年9月至2023年4月。在每个队列中，使用问卷调查来评估生殖因素。主要预测结果是出现子宫内膜癌的时间。采用Cox比例风险模型计算风险比（HR）和95％置信区间（CI）。在平均随访时间为16.5（6.4）年的332，625名妇女中，检测到1005例子宫内膜癌病例（均数【标准差】年龄为54.3【10.4】岁）。随着分娩次数的增加，子宫内膜癌的风险呈剂量依赖性减少（≥5次分娩与无产妇【参考组】：HR为0.37，95％CI为0.26-0.53，P趋势值<0.001）。与13岁以下初潮相比，17岁或以上初潮的HR为0.64（95％CI为0.48-0.86，P趋势值<0.001）。晚绝经（年龄≥55岁）与绝经年龄最年轻类别（<45岁）相比，HR为2.84（95％CI为1.78-4.55，P趋势值<0.001）。初产年龄、激素疗法和哺乳与子宫内膜癌风险无关。这一大规模的合并研究发现，晚发育、早绝经和更多次的分娩与子宫内膜癌的风险显著相关。这些来自亚洲前瞻性研究的令人信服的结果，进一步增加了有关生殖因素与子宫内膜癌关联的证据。

Despite evidence of an association between reproductive factors and endometrial cancer risk, prospective studies have been conducted mainly in non-Asian countries.To assess the association between reproductive factors, such as number of deliveries, age at menarche, or menopause, and endometrial cancer risk.This cohort study used pooled individual data from 13 prospective cohort studies conducted between 1963 and 2014 in the Asia Cohort Consortium. Participants were Asian women. Data analysis was conducted from September 2019 to April 2023.Reproductive factors were assessed using a questionnaire in each cohort.The main outcome was time to incidence of endometrial cancer. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and 95% CIs.A total of 1005 endometrial cancer cases were detected among 332 625 women (mean [SD] age, 54.3 [10.4] years) during a mean (SD) of 16.5 (6.4) years of follow-up. Increasing number of deliveries was associated with a decreased endometrial cancer risk in a dose-response manner (≥5 deliveries vs nulliparous [reference]: HR, 0.37; 95% CI, 0.26-0.53; P for trend < .001). Compared with menarche at younger than 13 years, menarche at 17 years or older had an HR of 0.64 (95% CI, 0.48-0.86; P for trend < .001). Late menopause (age ≥55 years) showed an HR of 2.84 (95% CI, 1.78-4.55; P for trend < .001) compared with the youngest age category for menopause (<45 years). Age at first delivery, hormone therapy, and breastfeeding were not associated with endometrial cancer risk.This large pooled study of individual participant data found that late menarche, early menopause, and a higher number of deliveries were significantly associated with a lower risk of endometrial cancer. These convincing results from Asian prospective studies add to the growing body of evidence for the association between reproductive factors and endometrial cancer.