Father's Day 2003 by Maggie Gallagher.
She quotes Alan Close, an Australian poet:
"'I have been the father of several terminations, all but one of which were clear mutual decisions -- as much as any can be. That one exception was my girlfriend's last-minute choice. She had been my partner for several years, but our relationship was in turmoil after we had become involved with other people.'
Alan is 47 now and childless. The turmoil and the drama of that long-ago time have faded. The agony and the ecstasies are over. He's left with memories of what will never be: a boy they had already imagined, named Jack.
'He would have been 13 this month. I can imagine, too easily, his gangly cockiness, the sullen, aggrieved tone of his voice and, also too easily, the frustration and fierce protectiveness this arouses in me as his father.'
Many thanks to The Raving Atheist for sending me this link.