Here is the fact that everyone debating abortion should know. There is no association between its legality and its incidence. In other words, banning abortion does not stop the practice; it merely makes it more dangerous.

The abortion debate is presented as a conflict between the rights of embryos and the rights of women. Enhance one, both sides sometimes appear to agree, and you suppress the other. But once you grasp the fact that legalising women’s reproductive rights does not raise the incidence of induced abortions, only one issue remains to be debated. Should they be legal and safe or illegal and dangerous? Hmmm, tough question.

There might be no causal relationship between reproductive choice and the incidence of abortion, but there is a strong correlation: an inverse one. As the Lancet’s most recent survey of global rates and trends notes, “The abortion rate was lower … where more women live under liberal abortion laws.”

Why? Because laws restricting abortion tend to be most prevalent in places where contraception and comprehensive sex education are hard to obtain, and in which sex and childbirth outside marriage are anathematised. Young people have sex, whatever their elders say; they always have and always will. Those with the least information and the least access to birth control are the most likely to suffer unintended pregnancies. And what greater incentive could there be for terminating a pregnancy than a culture in which reproduction out of wedlock is a mortal sin?

How many more centuries of misery, mutilation and mortality are required before we understand that women – young or middle aged, within marriage or without – who do not want a child may go to almost any lengths to terminate an unwanted pregnancy? How much more evidence do we need that, in the absence of legal, safe procedures, such sophisticated surgical instruments as wire coathangers, knitting needles, bleach and turpentine will be deployed instead? How many more poisonings, punctured guts and burst wombs are required before we recognise that prohibition and moral suasion will not trounce women’s need to own their lives?

The most recent meta-analysis of global trends, published in 2012, discovered that the abortion rate, after a sharp decline between 1995 and 2003, scarcely changed over the following five years. But the proportion that were unsafe (which, broadly speaking, means illegal), rose from 44% to 49%.

Most of this change was due to a sharp rise in unsafe abortions in West Asia (which includes the Middle East), where Islamic conservatism is resurgent. In the regions in which Christian doctrine exerts the strongest influence over legislation – west and middle Africa and central and south America – there was no rise. But that’s only because the proportion of abortions that were illegal and unsafe already stood at 100%.

As for the overall induced abortion rate, the figures tell an interesting story. Western Europe has the world’s lowest termination rate: 12 per year for every 1000 women of reproductive age. The more godly North America aborts 19 embryos for every 1000 women. In South America, where (when the figures were collected) the practice was banned everywhere, the rate was 32. In eastern Africa, where ferocious laws and powerful religious injunctions should – according to conservative theory – have stamped out the practice long ago, it was 38.

The weird outlier is eastern Europe, which has the world’s highest abortion rate: 43 per 1000. Under communism, abortion was the only available form of medical birth control. The rate has fallen from 90 since 1995, as contraception has become easier to obtain, but there’s still a long way to go.

Facts, who needs ‘em? Across the red states of the US, legislators have been merrily passing laws that make abortion clinics impossible to run, while denying children effective sex education. In Texas, thanks to restrictive new statutes, over half the clinics have closed since 2013. But women are still obliged to visit three times before receiving treatment: in some cases this means travelling 1000 miles or more. Unsurprisingly, 7% of those seeking medical help have already attempted their own solutions.

The only reason why this has not caused an epidemic of abdominal trauma is the widespread availability, through unlicensed sales, of abortion drugs such as misoprostol and mifepristone. They’re unsafe when used without professional advice, but not as unsafe as coathangers and household chemicals.

In June, the US Supreme Court will rule on the constitutionality of the latest Texan assault on legal terminations, the statute known as HB2. If the state of Texas wins, this means, in effect, the end of Roe v Wade, the decision that deemed abortion a fundamental right in the United States.

In Northern Ireland the new first minister, Arlene Foster, who took office on Monday, has vowed to ensure that the 1967 abortion act, which covers the rest of the United Kingdom, will not apply to her country. Women there will continue to buy pills (and run the risk of confiscation as the police rifle their post) or travel to England, at some expense and trauma. Never mind the finding of a High Court judge: “there is no evidence before this court that the law in Northern Ireland has resulted in any reduction in the number of abortions”. It just warms the heart to see Protestant and Catholic fundamentalists setting aside their differences to ensure that women’s bodies remain the property of the state.

Like them, I see human life as precious. Like them, I want to see a reduction in abortions. So I urge states to do the opposite of what they prescribe. If you want fewer induced abortions, you should support education that encourages children to talk about sex without embarrassment or secrecy; contraception that’s freely available to everyone; an end to the stigma surrounding sex and birth before marriage.

The religious conservatives who oppose these measures have blood on their hands. They are responsible for high abortion rates; they are responsible for the injury and death of women. And they have the flaming cheek to talk about the sanctity of life.