Proof of marriage and childbirth, first of all, is to prove that you have never been married or given birth to a child. As far as reality is concerned, it is not easy or important to prove whether you have been married. Here, the core is whether you have given birth to children, which is the key to the problem.
But how can you prove that you gave birth to a child? First, it is your neighbor; Second, your colleagues at work; Third, friends in your life circle.
Generally speaking, a person has a fixed residence, a fixed workplace and a fixed life circle. So whether she has given birth or not, people around her can see at a glance, that is, the so-called "eyes of the masses are discerning." For this kind of person, it is very simple to prove whether she has given birth to a child: the village (neighborhood) Committee is fully aware of the situation and can naturally give you a certificate and stamp. This is legally valid. However, if you don't live in this situation, no one can give you proof, and the village (neighborhood) Committee or your unit that represents the "eyes of the masses" will not give you this proof. In this case, the only way to prove whether you have given birth to a child is a medical certificate.
So in general, you can judge whether you need to go to the hospital for examination. In other words, under normal circumstances, as long as there is a certificate from the village (neighborhood) Committee or your work unit. But if you can't stamp the seal of the village (neighborhood) Committee, you can't prove whether you have given birth. In this case, it is reasonable for the family planning department to ask you to go to the hospital for examination.
In addition, if the family planning department has enough evidence to suspect that you have a birth history, they can ask you to go to the hospital for examination even if there is a certificate from the grassroots organization.
Good luck!