First of all, the stories of Di Xin and Shi are political tools to implement the honey trap. One is used to alienate Dong Zhuo and Lu Bu, and the other is used to confuse the king. On the day they are selected, it is impossible for them to have children, because the trainer will definitely think of this problem. If she has their children, they may change their minds for the sake of them.

Yang Zhaojun gave birth to a child, because he is the peace envoy of our country and Tubo country. There is nothing wrong with her not having children. Having a child is more conducive to our peace with the Tubo countries.

The last one is Yang Guifei, the wife of Emperor Xuanzong of Tang Dynasty. I think it may be Yang Guifei's own physical problems, because neither he nor their husbands have children, or it may be that Tang Xuanzong refused to let her have children, in order to prevent the country he laid from changing her surname.

The above is my opinion, I hope it will help you.