Well, one of the purposes of marriage is to produce children. It's one of the petitions in the Great Litany at the beginning of the ceremony:
"That they may be granted children for the continuation of the race, and all their petitions which are unto salvation, let us pray to the Lord."
However, I agree that it's not the sole purpose, nor would it be a crime to not reproduce in such a situation. Obviously an issue like this would benefit from counseling with a priest before marriage. I would also say there probably isn't an Orthodox answer. Not all questions have an Orthodox answer. Like "Should I drink regular or diet soda? Diet soda, because a lower intake of calories imitates the fasting that Christ did during his forty days in the wilderness." Haha...
In addition, Joseph was betrothed to the Theotokos, and they never "consummated" their marriage, to use the aforementioned RC terminology. Does the RCC chastise the Ever-Blessed Virgin for not producing children with Joseph? How about them apples?