Procreation As the Purpose of the Creation of the World: Chagigah 2b
Gd and the two parents as partners in creating a child: Kiddushin 30b
Having children depends upon Mazal: Moed Katan 28a
Where it will cause the birth of wicked people: Berachot 10a
HaShem puts one who is married without children in Ex-Communication: Pesachim 113b
Mourning for one who dies without children: Moed Katan 27b
Whether women are obligated in Procreation: Shabbat 111a; Eruvin 27a; Kiddushin 34a, 34b-35a
Statement against those men who travel to Israel, leaving their wives alone for long periods of time: Gittin 6b
Postponing divorce for the sake of the children: Eruvin 41b