Children are blessings from God. They are the heritage of God. Parents love it to see their children around. It makes a happy home when there are children as the fruit of the marriage. The joy of every woman and the joy of every man is to be a mother or a father. There is undeniable blessedness in the fruit of children in the home.
I have observed that couples in my community tend not to be happy when they don't have children in their marital union. Some people don't even have fulfillment in adopting children. A home without children is mostly unhappy. They feel unfulfilled when married people turn around and see that they do not have children.
There is truly unhappiness when children die. But this is only for us as humans. The Bible offers comfort and consolation about the death of children. There is that assurance that young children might make it to heaven at their death because they are innocent.