IT is not hard to see why Glasgow senior midwives Mary Doogan and Connie Wood struggled with the fact that, when medical terminations were moved to their labour ward, they would have to supervise and support staff carrying them out.

They are Roman Catholics, after all, and in their minds they would have seen themselves as accomplices - culpable in acts that were to them a grave offence to human life.

It was natural they would want to refuse. That's how we expect conscience to work: if you think something is very wrong, you want no part in it. One wonders at what level of remove from the termination process these midwives would have had to be to feel comfortable. And that is precisely why the decision made by the Supreme Court last Wednesday, regarding their right to opt out of such tasks, is the right one.

The question the court was looking at was the scope of the right to conscientious objection under the Abortion Act 1967. It provides that "no person shall be under any duty … to participate in any treatment authorised by this Act to which he has a conscientious objection". What was as at issue was what "participate" really meant. Did it mean only hands-on actions, or could it incorporate any wider work in connection with the process, such as supporting staff directly involved in dealing with terminations?

In 2012, the Court of Session in Edinburgh ruled that in the case of the two midwives, the right extended "not only to the actual medical or surgical termination but to the whole process of treatment given for that purpose". However, last week at the Supreme Court the judges decided that "participate" meant taking part in a "hands-on capacity".

That decision was right, because when we start extending out conscientious objection to anything beyond the actual act itself we risk the consciences of a minority of people quite distant from that act disrupting the process for everyone. As the British Pregnancy Advisory Service and the Royal College of Midwives put it: "Such a broad and unprecedented interpretation of conscientious objection, applicable across the UK, would effectively have enabled a tiny number of staff opposed to abortion to make women's care undeliverable in many NHS settings."

Although the NHS is bound by the Abortion Act to tolerate such beliefs and acts of conscience, the system can only go so far to accommodate them. In other words, if we are going to allow such conscientious objection to exist within such a system, it has to be restricted. In fact, I would argue that it is probably better not there at all - and has no place in an evidence-based health system driven by research and the principle of delivering the best health outcomes to women and wider society.

Conscientious objection has long hampered the ability of health systems across the world to provide access to abortion to women, even where it is legal. Research has shown that doctors who object to abortion, who know they are supposed simply to refer on patients, don't always do so quickly - they also do not always provide accurate information.

In South Africa, widespread conscientious objection limits the numbers of willing abortion providers, and thus access to safe care - and the number of unsafe abortions has not decreased since the legalisation of the process in 1996. Campaigners Joyce Arthur and Christian Fiala have argued against the very idea of conscientious objection to abortions, which they say "is based on a denial of the overwhelming evidence and historical experience that have proven the harms of legal and other restrictions, a rejection of the human rights ethic that justifies the provision of safe and legal abortion to women, and a refusal to respect democratically decided laws".

The language in this debate is often emotive. One of the things frequently said about these two midwives is that they entered the profession of midwifery to bring lives into the world, not to kill them off - as if midwifery was some sacred profession, concerned solely with the child's life, not the health and experience of the mother. But throughout history, midwives have been the deliverers of abortion as well as babies, and were once hunted down as witches for their role in the practice.

We live in a world that ­increasingly believes in the need to conduct ourselves ethically, whether as consumers or workers. If you know something is happening and think it is wrong, goes the thinking, you should not tolerate it or be complicit in it. In that sense, we can sympathise with Doogan and Wood. But conscience comes in many forms and reflects many different beliefs. It is worth bearing in mind that bioethicist Bernard Dickens describes the stance of pro-choice healthcare workers as "conscientious commitment", pointing out that "religion has no monopoly on conscience".

The truth is that pro-lifers already have a special privilege not afforded to most consciences: they have been given permission to opt out. They do not need that expanded, or further legitimised - particularly not at the expense of the health of those for whom they care.