It doesn't. It has to do with you asking Iceaura what he knows about other cultures and how they view the issue. If you check the whole link you will find your answer as to life expectancy etc. Which of course has nothing to do with the issue since you can only choose to have an abortion within specific ages and it is in the West (many can live longer) where abortion is in the decline. We are also having less babies. Asia and Africa you will agree are substantially more religious than we are in the evil secular liberal west and yet they seem unable to stay away from abortion clinics.
But I did find this. Its simply an excerpt and the piece is quite long so you would really have to read the whole thing. Feel free to respond to it later after you have digested it all.
If viññāṇa does not in any way subtend the karmic process from individual to individual and may even be completely episodic within the context of an individual life, then (1) I see no reason to interpret viññāṇa as anything other than consciousness or some such equivalent, and (2) Buddhism need not take viññāṇa to be present at any particular point in the process of embryonic development. That is, viññāṇa or consciousness is present whenever one would customarily say it is and that could be just as well at viability as at conception. In fact, we would generally hold consciousness to be present only when, minimally, the cerebral cortex develops and perhaps later. (13) Thus, even though a Buddhist would hold that consciousness provides the platform for mind and body, making any conscious being a living being worthy of moral consideration, it is not clear exactly when such a point might first occur. Furthermore, even if scriptural sources would locate this point early on in the embryonic process, a Buddhist could still coherently question any such time designation as potentially arbitrary mainly because, as I have argued, Buddhism lacks any comprehensive theory or deep-level principle that requires the presence of consciousness or an intermediate being at any particular point in the biological process of human development.
In fact, Keown admits that a Buddhist could hold the above position as the Buddha laid down several conditions covering ontogeny, some strictly biological and mainly regarding coitus and the mingling of sperm and, mistakenly, "menstrual blood." That is, even on Keown's analysis, Buddhism traditionally separates the biological basis for life from the individual life itself. Thus, a fertilized ovum is arguably a necessary but not sufficient condition for a new life. Rather, one requires the presence of the full complement of groups including viññāṇa to complete the development of an individual life. However, this allows "the material basis for life to arise on its own" (Keown 81), which Keown admits seems to contradict the assumption that the biological and spiritual basis must always arise together. Keown replies that if an unanimated conceptus is possible, its long-term survival is not for it is not "a new individual," and therefore "from the standpoint of Buddhist doctrine it would seem impossible for it to develop very far."
The justification for this claim is the Buddha's statement "that if consciousness were 'extirpated' from one still young, then normal growth and development could not continue" (Keown 81). Incidentally, this claim also forms the basis for Keown's view that PVS patients (those in a "persistent vegetative state") are still individuals worthy of moral protection and should not be ruled as dead, as some advocates of a higher-brain definition of death would allow. That is, their continued and stabilized biological existence (some can live on for decades) demonstrates the presence of viññāṇa and hence individual life.
However, a liberal Buddhist could claim that while the loss of viññāṇa might curtail growth and development, it is not clear that viññāṇa's never having arisen need affect the biological development of the material basis of an individual's life. Indeed, one might argue that (1) because "extirpation" of consciousness from one who already possesses it usually involves physical trauma, of course we would expect normal growth and development to stop; or (2) even though viññāṇa is essential to the life of an individual and its irretrievable loss signals the individual's demise, it doesn't follow that the mere biological platform and its growth and development signal the inevitable presence of viññāṇa. (14) That is, it doesn't follow that viññāṇa, however we interpret it, is essential to the life of the biological organism. Especially if, as Keown suggests, Buddhism allows the presence of the material basis of life without that of the gandhabba, then I don't see how Buddhism can rule out the possibility of simply a more extended existence of that material basis without viññāṇa. The biological basis of life may be organically integrated in the manner of a functional organism, but it is not itself the same thing as an individual life. I see no compelling rationale, based on Buddhist principles as articulated in the early scriptures, absolutely requiring the 'individual life begins at conception' point of view of radically pro-life antiabortionism.
I grant that the early Buddhist scriptures do seem to have a somewhat pro-life orientation. Yet, on closer inspection, I'm not sure the footing is there mostly because of the lack of a theory of ensoulment. Furthermore, had Buddhists of the time faced the bewildering medical possibilities of the late twentieth century, I'm not at all sure how doctrine would have evolved. For example, anencephaly, PVS and various other comatose conditions where patients exist in only the most minimal sense and on life support, not to mention transplant surgery, the advances in human genetics, and so on surely pose a challenge to traditional ways of regarding the human body. Many of these cases are, to my mind, simply waved aside by Keown (or his version of Buddhism). To claim that the pro-life stance of Buddhism simply means that PVS patients are fully alive (15) is not to do justice to the complexities of the cases or of Buddhism, both of which suggest that 'life' is an extremely complex 'dependently arisen' phenomenon. (16)
Either we are intentionally taking life or we are not, and if we are, then we violate Buddhism's First Precept. The response a Buddhist may make, such Ochiai Seiko's above, is in essence, "Yes, we should always avoid the ending of a life, no matter how insignificant it may seem." But 'life' is an ambiguous term, and the ending of one form of life in the service of others is not necessarily prohibited in Buddhism. And if one's intention is not so much to end a life as to rescue others, then we are not dealing with a simple case of intentionally killing. In other words, compassionate action will always involve weighing up the full range of circumstances that bear on a situation or action. On this view, the point of the First Precept is to disqualify intentional killing where the clear purpose is to end an individual life. Such an action can never be compassionate in Buddhist eyes. However, questions as to the status and nature of the lives one weighs in such tricky situations where interests clash are obviously relevant. If we are talking about the lives and interests of mothers and fetuses, fetuses and families, or fetuses and communities (such as in times of famine), then we are directly faced with the issue of the relative moral standing of different sorts of life. What I have argued here is that because Buddhism allows a distinction between the biological basis of life and its higher cognitive as well as affective aspects and insists that an individual human life requires the conjunction of all such aspects, no Buddhist need equate a presentient fetus with a sentient human. Thus, Ochiai's insistence that in dealing with the messiness of everyday living, abortion may qualify as a compassionate response need not contradict Buddhist principles. Especially if we are dealing with the material platform of an individual being before the point of cerebral development sufficient for the developed capacity for consciousness, then the moral seriousness of its claim to life may well be outweighed by other considerations.
http://www.buddhistethics.org/5/barnh981.html