4.32 What if people cannot have children?
A couple’s desire to start a family is a very natural thing, and part of the wonderful way God created us humans. It can be very sad if it turns out that a couple cannot conceive children. It is wonderful when this situation can be resolved through medical means. However, not everything that is possible is also right: artificial fertilisation, for example, leads to a number of ethical problems.
A child is always a gift that ultimately comes from God; it is not a "product" manufactured in a laboratory. Sometimes accepting the situation is the only solution, even though this may go against the natural desires of a couple. Adoption is also a possibility. And a marriage can also be truly fruitful in other ways, even without children.
What can spouses do when they do not have children?
Should the gift of a child not be given to them, after exhausting all legitimate medical options, spouses can show their generosity by way of foster care or adoption or by performing meaningful services for others. In this way they realize a precious spiritual fruitfulness. [CCCC 501]
What can a childless couple do?
Married couples who suffer from infertility can accept any medical assistance that does not contradict the dignity of the human person, the rights of the child to be conceived, and the holiness of the sacrament of Matrimony.
There is no absolute right to have a child. Every child is a gift from God. Married couples to whom this gift has been denied, even though they have exhausted all permissible medical means of assistance, can take in foster children or adopt children or become socially involved in some other way, for instance, by caring for abandoned children. [Youcat 422]
The Church pays great attention to the distress of infertile couples, she cares for them and for this very reason encourages medical research. Science, however, is not always able to respond positively to the desires of numerous couples. I would therefore like to remind spouses in a condition of infertility, that this does not thwart their matrimonial vocation. Spouses are always called by their baptismal and matrimonial vocation itself to cooperate with God in the creation of a new human life. The vocation to love is in fact a vocation to the gift of self, and this is a possibility that no physical condition can prevent. Therefore, whenever science finds no answer, the answer that gives light comes from Christ. [Pope Benedict XVI, To the Pontifical Academy of Life, 25 Feb. 2012]