Well, now we're kind of branching out. In the stated situation where the zygote/embryo/fetus cannot possibly survive for a very short period if time and most likely in agony, it's a hell of a lot more than "inconvenient", for either party.
You frame the statement as if the mother is always doing this wholly out of selfishness. The zygote/embryo/fetus clearly cannot self-advocate, so the mother must weigh the costs for both. Sometimes, abortion, especially in the aforementioned scenario, IS the most humane decision for both parties. It's immoral to subject a child to a short life of great suffering, or a long one of great suffering. If anything, deciding to have a child should involve just as much moral wrangling as abortion, maybe more.