Background China is the country with the highest prevalence of diabetes in the world.Therefore,it is necessary to explore the risk factors of diabetes.So far,no agreement has been reached on whether parity(number of live births) has a relationship with the incidence of diabetes in women or not.Objective To explore the influence of parity on the risk of type 2 diabetes in women,providing fertility counseling for women of childbearing age.Methods This study was conducted in 1 815 nondiabetic women aged ≥40 who met the criteria of this study.They were recruited from those who participated in the epidemiological survey of cancer risk in Chinese patients with type 2 diabetes mellitus in Luzhou,Sichuan from April to November 2011.According to self-reported parity,they were divided into 1-birth group(n=1 115),2-birth group(n=403),3-birth group(n=173),and 4 or more births group(n=124).All groups received a follow-up from June to November 2016,during which the blood glucose levels were recorded and compared.Logistic regression analysis was used to explore the relationship of parity with type 2 diabetes.Results Compared with baseline,during the follow-up period,all participants showed no significant changes in fasting plasma glucose(FPG) levels(P>0.05);1-birth and 2-birth groups demonstrated lower 2-hour plasma glucose(2 hPG) levels after an oral glucose tolerance test(OGTT),but other two groups presented higher 2 hPG levels after OGTT(P<0.05).The rates of developing type 2 diabetes in all the participants,1-birth group,2-birth group,3-birth group,and 4 or more births group were 9.15%(166/1 815),6.64%(74/1 115),9.68%(39/403),19.65%(34/173),and 15.32%(19/124),respectively.The 3-birth group showed a higher rate of developing type 2 diabetes compared with 1-birth group,and 2-birth group(P<0.05).And the 4 or more births group presented a higher rate of developing type 2 diabetes than 1-birth group(P<0.05).Multivariate Logistic regression analysis showed that compared with women having 1 birth,the risk of developing type 2 diabetes was almost the same in those having 2 births〔OR(95%CI)=1.216(0.797,1.856)〕,but it was 2.355 times in those having 3 births〔95%CI(1.474,3.761)〕,and was 1.860 times in those having 4 or more births〔95%CI(1.058,3.270)〕.Conclusion Multi-parity may increase the risk of type 2 diabetes in women.To prophylactically reduce this risk,it is recommended that women have one or two children.