There are certainly practical distinctions there, but how does this make them not "morally equivalent"? What does that even mean?
I found the thrust of this article horrific (from a pro-life and anti-infanticide POV), but I thought the authors actually made a few good points.
I have long been baffled by the pro-choice tendency to segregate reproductive "what I do with my body" from run-of-the-mill, everyday "what I do with my body". The strongest argument for legalised abortion is "You can't tell me what to do with my body" - but the government does tell you what to do with your body, all the time. Everything we do involves our bodies, because we're physical beings. If we are told to pay our taxes, we have to use our bodies to do it - either typing with our fingers on the keyboard, using our mouths to tell someone else to do it, walking to the post office, whatever - even just using our brains to make the calculations is a physical event. In that sense, the government is "enslaving" our bodies. Same with pretty much any law - the use of our bodies is restricted in how far we press our feet on the accelerator, whether or not we're allowed to use our hands to wield a gun, build a backyard fence more than so many centimetres high... everything.
These authors recognise that. They don't get precious about the distinction between carrying and raising a child, but recognise that both are bodily processes that involve a mother - and if a mother can legally kill her child because nurturing him in utero is causing her mental and/or physical distress (which she can), and if a newborn is fundamentally no different to a fetus (which he isn't), then surely it's logical that she be allowed to kill her child because nurturing him outside the womb is causing her mental and physical distress?
Now, the obvious answer to that is "But someone else could take care of him", but that question presupposes that newborns/fetuses have moral worth, ie that it's morally preferable to allow them to live; which the authors haven't granted in the article. At any rate, there are, at least theoretically, situations in which a woman couldn't hand the baby off to someone else. Say a woman was on a plane with her newborn baby and it crashed, and she and the baby ended up on a desert island - little food and water, and the mother would be more likely to survive if she conserved her resources by not breastfeeding and spending her time hunting for food rather than caring for the baby. In that situation, would her killing her baby be morally indistinguishable from abortion? The baby is just as dependent on her body as if it were still in the womb; it will die without her, and only her, physical care.
And yes, like a PP, I would be interested to pin these "ethicists" down on just when they feel killing one's offspring is impermissible. I suspect they're shying away from the issue because they know darn well that any number is going to be arbitrary and contentious. Six months (the Lacanian mirror stage of development)? The individual age at which caring for the child is no longer mentally or physically burdensome for the parent?
Carrying their logic further, because adoptive parents have the rights to authorise any medical procedures a biological parent would, could a couple adopt a special needs baby (or even a "normal", healthy baby, according to the terms of their argument, if they lived in an abortion-on-demand area) and then perform a "post-birth abortion"?
It's all quite fascinating, in a horrific sort of way.