Study population
A brief overview of the UK Biobank study design is provided below, as the study design and methods have been reported elsewhere in detail previously[24]. In short, the data used in this study came from the baseline survey at 22 assessment centers throughout England, Wales, and Scotland from 2006 to 2010, a total of 502411 participants (5.5% response rate) aged between 37 and 73 years. Data from 273325 women were available for our study, we excluded 478 participants with incomplete data on the number of live births and 352 participants who prefer not to answer. Among them, we considered only the subjects above 40 years of age at recruitment, as there are few deaths at younger ages[25] (Supplementary Figure 1). As a result, a total of 272494 women (99.7%) were included in this study. All participants provided written informed consent, and the study was approved by the North West Multi-Centre Research Ethics Committee and the Tulane University (New Orleans, LA, USA) Biomedical Committee Institutional Review Board.