Why? Because we remain deeply ambivalent about contraception - that greatest modern blessing, without which women would still be household slaves. The ignorance and stupidity of so many teenagers is the direct result of our ambiguous attitudes - surrounding them with sex, but denying them knowledge. The National Curriculum includes sex education half-heartedly in science lessons, with precious little useful contraceptive information, and parents are allowed to opt their children out of classes altogether.
If we were serious about teenage pregnancy there would be clinics with nurses available in every school. The Dutch have virtually no teenage pregnancies and they teach sex education from the first primary years. It does not promote more sex: their well-informed teen population embark on sex at a later age than ours.
But 35 years after the arrival of the Pill, we still have not learnt to love it as we should. The great liberator of the Sixties remains shrouded with fear, guilt and plain dislike. Much of that fear is deliberately generated by gleeful panics promoted by the moralising press and the Christian lobbies. But some springs spontaneously from the current woolly fashion for everything labelled "natural", homeopathic and non-invasive. Teenagers brought up on Body Shop designer greenism shudder at the thought of polluting their White Musk and Dewberried bodies with nasty chemicals.
The latest Pill scare last year, started by over-panicky guidance issued by the Committee on Safety of Medicines, lead to large numbers of women giving it up. As a result, abortions rose in the first months of this year by 3,000, at a time when the abortion trend was downwards.
Myths and half-truths still surround all methods of contraception, despite all those explicit magazine problem pages. Every survey reveals astounding fear and ignorance. Women look upon contraceptive options with less than glee: all that slimey rubbery stuff, nasty looking wire contraptions for the womb, elaborate "natural" methods with thermometers or computers and nightly urine tests - or the mighty Pill whose chemicals screw up your natural system, with God knows what long-term effects. Too many women flee to sterilisation, often the wrong drastic choice - 42 per cent in the US, (one fifth later regret it).
However, contraception is easy and, for virtually everyone, problem-free if women would only believe it. The unloved IUD, for instance, is a tiny little device nowadays. As for the Pill, its very low dose, compared with the early days, is extraordinarily safe. Yet the myths go on forever: it messes you up and might kill you through thrombosis. If you take it too young before your body is settled, it could screw up your fertility forever. It must not be taken for too long. Its effects linger on in the body after stopping, delaying the chances of getting pregnant. How many of these statements do you believe? They are all untrue.
Women can take the Pill forever. You can get pregnant within 12 hours of stopping - a fact that many forgetful women learn to their cost. There is no medical reason why very young girls should not take the Pill. Of the millions who take it in Britain, only four or five die of thrombosis - a far safer record than virtually every other widely taken drug.
But we are not good at risk assessment. And who talks of the benefits? The Pill protects against ovarian cancer, of which 4,300 women die a year. Women who take the Pill have half the risk of contracting this cancer and the protective effect lasts for 15 years after they stop taking it. But how often do you hear that fact promoted?
Last week Elof Johanssen, director of the Population Council, the leading US non-profit contraception research organisation, was in Britain castigating America's continuing catastrophic teenage pregnancy rate, with 57 per cent of all US pregnancies unintended. Britain, though not as bad, he says, is closer to the US in its confused attitudes and poor figures, than to the rest of Europe. He blames the religious and moral lobbies for obstructing effective sex education. (He is one of those Swedes we tend to mock for their earnestly open approach to sex: he gave menstruation parties for his daughters' coming of age.)
Whatever the social problems caused by failing to get contraception to all who need it in the West, the population explosion in the developing world is the great problem of the next century: world population will double in the next 50 years. Johanssen's research shows that wherever contraception is easily available to third world women, offered them by other women and not by doctors, women take to it at once. If it is left to men, nothing happens. In most developing countries it is the men who want more babies than they can support, not the women. In Ghana, for instance, men say they want 10 babies, women want five. "When you make contraception cheaply available to all women, they take it immediately. If women chose how many children to have, 95 per cent of the world population problem would be solved," he says.
Why, then, has so little been done? "The Catholic church and the Pope," he answers bluntly. Do they really have that much influence on governments? "In the key areas of over-population, especially francophone Africa and Latin America, the Catholic church may not control the government, but it runs most of the hospitals, missions and doctors." He expects growing wars over land, food and water, wars that will draw in the West as well, of which Rwanda was harbinger of far worse to come.
Fundamentalist Muslims and Protestants he also blames, but says it is parts of the world under Catholics influence where the population danger lies. He adds wryly that we may yet come to look back on Chairman Mao as a saviour of the world for his draconian one-child policy.
What can be done? "A new Pope, a new pro-contraception Catholic policy could change the outlook for the world overnight."