Um, no.
Sterility is not usually willed, and otherwise healthy, moral people who are sterile would be overjoyed if they conceived despite their apparent sterility.
Mutuality, love and concern for others which has been closed off to sharing those gifts with a third party are not fully healthy.
Your postulate that a third party must exist in a relationship of mutuality and care to be healthy is completely arbitrary and a non sequitor.
You view, then, as unhealthy, sex between a married couple who cannot conceive a child whatever the reason might be? Aristotle was liable to err you know.
http://www.youtube.com/watch?v=U0kJHQpvgB8