That research database is expanding all the time; indeed, by now, lucid consideration of the medical and statistical facts of abortion, the study of fully tested research results over a long period, even the discussion of the many changes in relevant societal aspirations since 1978, is overdue.
Whether such a discussion is possible today without the hysteria attendant on the debates of the 1970s is certainly moot, but that is no reason not to have one.
Sober, reasoned consideration of the law, its continuing relevance, and its manner of application, should always be uppermost in a society claiming to be "liberal".
It also seems to be a society exhibiting a colossal level of ignorance.
That we are a country with a high standard of living, a well-educated population with freely available sex education, contraceptives and contraceptive advice, yet continue to have so many "unwanted" pregnancies, suggests the state of the country's sexual health is in serious need of repair.
The scientific weight of evidence suggests very clearly that abortion has become, among some sexually active young women, a means of delaying pregnancy for a prolonged period.
One important Otago study noted in 2002 that in a large number of unwanted pregnancies, participants surveyed simply "did not think about" contraception at the time.
The study concluded: "While having children is natural, fulfilling and, from an ecological perspective, necessary, clearly many New Zealanders wish to delay this, which is consistent with the median age of child-bearing now being 30."
Three years ago - and not for the first time - the Abortion Supervisory Committee, which appoints certifying consultants who approve abortions, said it wanted the law changed because of what it described as its "de facto liberal interpretation", which enabled large numbers of terminations to be performed (18,211 in 2004, 17,934 last year), usually on the basis that a woman's "mental health" would be endangered by continuing with the pregnancy.
High Court judge Forrest Miller has now ruled that the committee actually has the power to dismiss doctors who are too liberal in permitting women to have abortions - but has never used it.
Justice Miller observed: ". . . the crude abortion rate is comparable to that of Canada and the USA, in which women enjoy a constitutional right to abortion.
Some consultants approve every request, and around 98% of abortions are authorised on the mental health ground".
The actual permitted grounds for an abortion are that proceeding with the pregnancy would pose a serious danger to the woman's life or physical or mental health; incest or sexual relations with a guardian; mental subnormality; and serious fetal abnormality.
Justice Miller pointedly remarked that Parliament appeared "untroubled" by the state of the abortion law, and the calls for reform had gone unheeded.
Of course it suits - and has suited - Parliament not to revisit the subject because there are no political winners in the debate.
That is a shameful situation.
There are many dimensions to the quandary women face when making what is invariably a difficult and emotionally harrowing decision.
Reviewing abortion law (which, it needs to be remembered, attempted to provide some protection for the unborn child), to further improve access to legal terminations would seem in the face of consistent statistics and in light of Justice Miller's opinion, to be a pointless exercise.
But what of the health issues involved? The implication of the data is that perhaps 20% of all pregnant women in any year potentially risk a serious mental health problem from undergoing the natural human function of motherhood.
Is our rate of abortion symptomatic of a sick, or of a healthy society, or is it simply an accurate reflection of some modern women's values? At the very least, we surely need to ask whether we have, in 30 years, achieved an appropriate balance of rights where unborn children still have little legal status and negligible privileges, and where abortion is by far the most common medical surgical procedure our young women receive.