I WAS on the baby's side when French detective Laure Berthaud sprinted along a Paris platform to catch a train to Holland where she had booked an abortion.

The star of the crime series Spiral was already more than 15 weeks pregnant - the legal limit for termination in France. Do you know what a 15-week foetus looks like, her doctor had asked her.

Perhaps the plot demands she remain pregnant. In any case a timely phone call to interview a crucial witness had her jumping off the train again. It was a relief to this viewer. Although I defend the right of those who choose it, a journey to abort is as bleak as a trip to Dignitas. You don't die. Your future child does.

It's a trip my former compatriots make in droves. Although Northern Ireland is part of the UK the 1967 Abortion Act does not extend to it. Instead, official figures show around 1,000 women a year travel to the mainland for an abortion. The Family Planning Association reckons that's half the true figure. The numbers are derived from the addresses women submit. Many give a false one.

It's a difficult and costly journey for more than one reason. When they arrive the women are not entitled to an abortion on the NHS. (It is free only for emergency care to people not normally resident.) So, including travel, they need to pay around £600 for the procedure if the pregnancy is under 14 weeks and up to £2,000 if it is later.

We can only speculate about how many can't afford it. But we do know that every week of the year at least 20 women make the journey. (The FPA's estimated 2,000 a year is about 40 a week.) Scots take note. While you are reading this, they will be sitting at an airport, boarding a ferry, checking into a hotel or handing over their money before climbing onto an examination table.

Take note because also this week new talks will start to take shape about devolving abortion to Holyrood. If power over this legislation does shift from Westminster, how will the law here differ from the one we currently share with England and Wales?

What will be the consequences for us and for our daughters?

The anti-abortion lobby sees the proposed power shift as an opportunity. Its deeply held ambition is to abolish the right to abortion in Scotland; or at the very least to narrow the time-scale when it can be obtained.

Labour fears that differentiation - more liberal laws in either England or Scotland - could set up cross border traffic of the sort Northern Ireland for historical reasons endures.

In Scotland in 2013, the latest year for which figures are available, there were 11,777 abortions, a sizeable number of them teenagers. In the unlikely event that abortion is abolished here, how many would have had the £600 - £2,000 necessary for a heart breaking trip south?

Unwanted pregnancies shouldn't be so common. Contraception is easily available and yet half of all pregnancies remain unplanned. I could argue that an unwanted pregnancy is irresponsibility writ large. But though the figures are dipping slightly, unwanted pregnancy remains a reality that needs to be treated judiciously and with compassion.

Our political representatives must discuss and decide how they will handle the legislation should it be devolved to them. Will they, like Northern Ireland, take a biblical view and restrict legal termination to cases that threaten a mother's life? Will they reduce the number of weeks gestation at which an abortion can be performed - or will they incline to be more liberal than England and Wales?

Time will tell. It's an issue that women need to stay alert to if they want to retain choice.

Abortion is not - nor should it ever become - something to be taken for granted. We argue about exactly when a life becomes human and about viability. But what no one disputes is that a human life would eventually emerge were the procedure not to take place. For that reason the legislation deserves respect.

In that ideal world where people avoid pregnancy by using contraception, politicians would make such important ethical decisions in an entirely non-partisan way.

But that ideal world is as illusory as the fictional drama Spiral.

In Scotland, we have a governing party whose reason for being is to wrest as much power as possible from Westminster. In that spirit it wants abortion law to be devolved. The Green Party agrees. Labour, by contrast is keen to leave well alone. The dispute almost derailed the Smith Commission on extra powers for Scotland until a fudge was agreed. Now the issue is coming back to be debated.

Labour's point is a fair one. How will Scotland differentiate itself sufficiently from Westminster to justify the bringing of the powers here yet remain sufficiently consistent to prevent the nonsensical cruelty of the Northern Irish experience?

I have a further concern. Scotland is a small country with the dangers that implies. Vested interest has access to power. The churches and pro-life groups are impassioned about this subject. Sister Roseann Reddy, of The Cardinal Winning Pro-Life initiative in Glasgow. is keen to have the legislation devolved in order to reform it. It has been suggested the powerful and wealthy Brian Soutar supports having it tightened.

Liberal thinking women are also determined. First Minister Nicola Sturgeon may rank among them for she sounds firm in her stance that abortion can continue to be carried out in the first 24 weeks of pregnancy. But we won't always have a woman of that view at the helm. Her predecessor seemed keener to keep all constituencies appeased. What about her successors?

Abortion is more emotive than the issue of Section 2A. The furore surrounding that shook Scotland when Donald Dewar was First Minister. It raked up prejudices and alarmed parents. It must have been difficult for the politicians to hold to their principles. But they did and the storm blew itself out. As a result the parliament looked stronger, more mature.

With new tax powers we'll see it tested again. Instead of complaining about Westminster's tight purse strings, it will have to dish out financial pain, make difficult choices, behave like a grown up legislature.

Abortion is thornier still because there is pain at its core. Those on both sides of the debate are sincere in their beliefs and in the certainty of their conviction. Storms lie ahead. Oddly I welcome them. Just as iron is proved in a forge so parliaments grow when they listen to all the arguments and make decisions that are in the best interests of the population they represent - rather than buckle to the most powerful interests. Which way will Holyrood choose?