‘My view is that the way to think of the foetus is to think of it as part of the pregnant organism. So that means we have one organism throughout the pregnancy and only at birth does this organism split and becomes two organisms.’
She opposes this view to what she calls the "foetal container model", in which "the pregnancy is literally a container and in the middle of the container there is a hollow in which sits the foetus—and there is no problematic part-whole relationship." (I take it that the key point here is the 'no problematic part-whole relationship', since spatially the fetus is literally contained. That is, the point is that the fetus is not contained in a pregnant organism the way a gift is in a box but is integrated into it in complex ways.) Unfortunately, we don't get Kingma's argument for the one organism view. There are other views than these two on the table. For instance, my own view of the matter, which I've mentioned before, is a two-organism view in which one organism is an integrated and dependent functional part generated in the other. (Of course, there is always some complication with what, precisely we mean by 'organism', since the term notoriously has no strict definition; but in the human case, I would say the same with 'human being': a pregnant mother is a human being who has another human being as a proper part.) The pregnant mother is not a mere container for the fetus; like Kingma's model, it is a part-whole model, since the fetus is literally and physically an interactive part of the mother, qua mother. But nothing about this, as far as I can see, requires that we hold there is only one organism. One potential worry about Kingma's one-then-two view is that birth is not a momentary happening,but a rather extended and complicated process; while the position looks like it would have a fairly simple way to distinguish organisms in the pregnancy case, it cannot actually do so. Is the relevant point the beginning of labor? The exit through the birth canal? The cutting of the umbilical? The first breath (after all, merely severing your hand doesn't make it a different organism, even though vital functions continue for a while)? There's no obvious way to answer this, and this seems to suggest that at least at some point in the process we can perfectly well have one organism that is still in some strict sense part of another, and if that's the case, it isn't clear why we shouldn't have said that all along -- or, at least, it seems that we could have said it much earlier just as well as later.
Kingma also considers ethical implications of her model. Unfortunately, it's not in the audio excerpt, and I find the written summary difficult to follow. She says,
‘When I do harm I have to cross through space to interfere with you. When I allow it to happen I just don’t get involved; it will happen regardless of my involvement. Pregnancy is not wired up like that. A pregnant woman who does anything at all does not cross space to interfere with her foetus.’
I find the idea that 'crossing through space' has much to do with whether one is doing harm difficult to understand. We obviously can harm ourselves. And we can clearly draw a distinction between doing and allowing even with regard to ourselves; most of what happens in our bodies we simply allow, although sometimes our allowance is more active and sometimes less. This is a worrisome fact, given that the position attributed to Kingma is that subject/object (or doer and done-to) break down, so that, in her words, "a doing-and-allowing construction (of harm) cannot be applied to pregnancy"; but if we're talking subject and object of actions, it is unclear how this can be the case. We can clearly be both subject and object of active harm to ourselves. Since the doing-and-allowing construction doesn't break down even in cases where there is obviously only a single organism and no question of pregnancy, it isn't clear at all to me why we would think it would break down here. The more obvious implication of Kingma's model (it is an implication of my own, as well) is that, at first approximation, for a mother to harm her fetus is to harm herself, and to harm a fetus is to harm the mother (although this is not necessarily a straightforward matter since part-whole relations are not always straightforward when it comes to harms); this is not, I suspect, where Kingma wishes to go with the matter. The assumption in the not-very-elaborated comments in the summary seems to be that Kingma holds that we cannot harm ourselves. This is, to say the least, very counterintuitive, and there are very good reasons to reject any such assumption. But it is perhaps an artifact of the summary rather than Kingma's own view.
Kingma is certainly right, though, that pregnancy is worth some thought. For such a common thing, it is remarkably overlooked when people talk about matters to which it would obviously be relevant.