Except the Lord build the house, they labour in vain that build it: except the Lord keep the city, the watchman waketh but in vain.
It is vain for you to rise up early, to sit up late, to eat the bread of sorrows: for so he giveth his beloved sleep.
Lo, children are an heritage of the Lord: and the fruit of the womb is his reward.
As arrows are in the hand of a mighty man; so are children of the youth.
Happy is the man that hath his quiver full of them: they shall not be ashamed, but they shall speak with the enemies in the gate.
Sarah and Abraham were chronically childless for pretty much their entire marriage, and ended up having just one. (Let's ignore the Hagar detour for a sec.)
Lot and his wife, may have had many kids biologically -- yet they were spiritually dead. Even the example of Eli, Samuel's priest, comes to mind. His sons were awful. Really sad.
The LORD is what matters. Whether you have one child, ten, or none.