When I see boys at my daughter’s school, all gangly limbs and scruffy hair, I wonder what my own son would have looked like. He would be nine now. He would have blond hair and blue eyes – his father and I share that colouring. He might have my prominent chin; definitely a grin all his own.

My son would also be unable to speak, walk or possibly even think for himself. He would have extra digits and a heart defect. The first child I conceived had Patau’s syndrome – also known as trisomy 13 – which affects 1 in 10,000 children. The condition typically results in death before birth, at birth or in the following few days.

Those with the syndrome can survive, though rarely do, into young adulthood, and that possibility has been enough to fuel my dreams. Over the years, I’ve allowed my imagination to run unchecked: I’ve seen him playing conkers, glued to a PlayStation, eating pizza.

Yet all this can only ever be conjecture, for I had a termination in my 13th week of pregnancy, two weeks before the turn of the millennium. It was an experience that has scarred me in ways I could never have foreseen. Put simply: my decision and its consequences have tortured me for the past nine years.

I’ve been unable to talk about it easily, unless with drink in hand, let alone write about the experience. I have felt out of step with the rest of the world, where the validity of abortion is a given and to admit to being uneasy about it seems to make you a traitor to any notion of “sisterhood”. But what has isolated me most, and this is the crucial point, is an overwhelming sense of shame.

Almost from the moment I awoke from the anaesthetic, I have deeply regretted my decision. Whichever way I looked at it, it felt then and it feels now like murder. When I signed the consent form that permitted staff to perform a termination, I killed my first child. Why? Because he would have been born disabled.

What a terrible admission that is. Although I suspect a few other women may be quietly nodding their heads in recognition, I’m not sure the majority of people will understand or sympathise with me. Some will find my action abhorrent; some do not approve of anyone criticising abortions.

The underlying issue is that society has changed in its attitude towards disability. After all, antenatal testing (and its consequences) is now so commonplace that when it was revealed last month that a new blood test had been developed that could detect Down’s syndrome, the news was greeted with what seemed to be universal delight.

“Science takes some stress off would-be parents,” was the New Scientist magazine’s take. And it’s true that significantly fewer women will endure invasive procedures – amniocente-sis or chorionic villus sampling (CVS) – that carry a distinct risk of miscarriage. In fact, recent research suggests that in the course of detecting and preventing the birth of 660 Down’s babies, 400 healthy foetuses are lost each year.

What no one seems to address is why this test – and the others – exists. The orthodoxy may be that it helps to prepare a couple for the possibility that their baby’s future will not be as they envisaged. But anyone who has been given a result that differs from the norm knows the expectation is that the pregnancy will be ended. Why give birth to a baby who is not “perfect” this time, when you might be “lucky” next time? The latest estimates are that more than 90% of Down’s syndrome pregnancies are terminated.

“There is an implicit message within the goals of prenatal testing”, says the disability ethicist Lisa Bridle, “that society believes that raising a child with disability is such a grave burden that it is both morally correct and medically appropriate to take expensive measures to ensure such children are not born.”

The popularity of antenatal testing is undoubtedly due as much to fear as to a sense of social responsibility. Few of us would undergo nerve-racking tests were we not frightened of the unknown. And as disabilities become less common – because of increased numbers of terminations – that fear increases.

My own situation came about almost by accident. A friend suggested that when I reached the 12th week of my pregnancy I should take myself off for a nuchal fold scan at a private clinic in central London. The idea didn’t seem to require much thought.

I was 34 and healthy; the pregnancy had so far been easy and exciting. I’d always been desperate to have a large family – and here we were, on the way. Yippee. “You get to see the baby much sooner than in an NHS clinic,” my friend told me, “and for £95, it’s a really lovely experience, very posh – worth it as a treat!” To me, in my gleeful hormonal state, it seemed a no-brainer.

My husband, as he then was, and I would head up to Harley Street that Thursday, see our cute little baby squirming on screen, get a picture and then head off for some Christmas shopping. Almost as soon as we arrived at the clinic, that cosy, festive mood passed.

After a blood test, we were ushered into the consulting room, where a charming doctor covered my tummy in gel to ease the passage of her scanner, and pictures appeared on the small black-and-white screen at the side of the bed. My husband and I may have been making the standard jokes to each other about whom the foetus resembled, but we quickly noticed that our doctor was not joining in.

She was quiet and focused, taking down numbers. A few minutes later she had the test results. At that point she told us: “Statistically, you’ve a one in four chance of serious, life-threatening abnormality. I’m certain you are that one.” Nine years on, I can still hear the scream I let out. I can also remember biting my hand: I didn’t want the other mothers waiting outside to hear me and feel a jolt of fear.

We were advised to return the following day, when a professor would offer a second opinion. Twenty-four hours later, the scan played out the same way. Now I could hear the professor saying he could see on screen that my child had extra digits on his hands and feet, and that his forebrain had not divided in two. All I could see was my dearly wanted baby, kicking and wiggling just like any other foetus.

I was torn between staring at him and not looking at all, imprinting him on my brain and wanting to forget. The doctor performed a CVS on me – the test for Down’s and other abnormalities.

Tears were rolling down my face. He then told me that although he was in no doubt my baby had either Patau or Edwards syndrome (the effects are similar), he would send off the placenta sample for examination, and the results would be back early the next week.

And he gently suggested that I book an immediate termination – before the results were even due – as Christmas was just over a week away and it would be my last chance to have an abortion before the new year. As I was already 12 weeks pregnant, waiting any longer would mean having to endure labour, rather than a “neat” termination under general anaesthetic. I felt confident that he was right; that misdiagnosis was impossible. What nobody told me, then or later, was that not everybody terminates such a pregnancy.

That I could have carried the baby to full term. The baby might even have survived for years – albeit with a serious and life-limiting set of disabilities. I numbly watched the clinic’s secretary arrange, through my GP’s practice, for a termination three days later at our local maternity hospital.

When I tried to speak to my GP – whom I had known for more than five years – she made it plain she had no time to discuss my situation. Was it because I had gone to a private clinic, or because she disapproved of terminations, or just because it was a Saturday morning and she couldn’t be bothered? I never knew. But she left me feeling worse – alone, scared, unimportant and filled with guilt.

My husband, family and friends were as kind as possible – and as shocked. None doubted that the termination was for the best. “Put it behind you,” were the four words I became accustomed to hearing. And in many ways they were right and fair. The decision was not mine alone, anyway: my husband was convinced of the correctness of this course of action, and his point of view was as valid as mine.

He was worried for my health, too – would carrying such a sickly child put me at risk? We knew so little. We struggled on till Monday and drove to the hospital for the operation. Here, I met the one person who allowed me to question what was happening – an anaesthetist who threw everyone out of the room and sat down on the bed to ask whether this was what I really wanted.

I wish she had been there 24 hours earlier – by this time it was too late. I’d lost all willpower, all ability to do anything but cry. I said: “Yes, I’ll do this.” And with that I gave permission – and I cannot put this any other way, try as I may – to murder my unborn baby. Premeds were given, and I was placed on a trolley and wheeled down to theatre. I didn’t stop crying once. I dimly remember repeating, “No, no, no.”

And then I remember waking up crying, and it was over. A few days later, the CVS result came back in the post. My baby had been trisomy 13 – and a little boy. I then learnt of a tiny, impartial charity called ARC – Antenatal Results and Choices – which had been set up to provide information to parents who discover that their child may have a disability or disease. I steeled myself to call one of its helpers one night.

I don’t think I told her my story; I think I just sobbed down the phone and she listened. I should have thanked her, but I wasn’t capable of seeing or saying anything outside my bubble of pain. Had I been offered professional counselling at any stage in this chain of events, I’ve no doubt that my experience would have been different. I didn’t know I could ask for it, and I certainly wasn’t recommended any.

Christmas came and went, and I forced myself back into work on Boxing Day to try to preserve a little sanity. My colleagues were wonderful, but I was so ashamed of having had a termination that I said I’d miscarried. I couldn’t face what I felt would be inevitable disapproval of my decision to have an abortion. The weeks went by, and friends and family stopped asking how I was.

I found myself pregnant again a few months later, but that pregnancy ended in miscarriage on the exact weekend my son should have been born. I suppose it was inevitable I would think it was some sort of natural justice or punishment. The trail of misery went on.

My marriage ended six months later. I went on to have two more miscarriages in another relationship. I felt cursed. Finally, tests revealed that there was a reason for at least the miscarriages: I had antiphospholipid syndrome, which means my blood clots too easily, usually preventing pregnancies from taking hold. Why this did not stop the first one, no one has been able to tell me. Diagnosis did mean, however, that when I became pregnant in 2005 I could receive treatment to stop me miscarrying: daily injections of heparin to thin the blood.

Then came the day when I had to decide about antenatal testing. I was nearly 40 by this time, and my risk of having a baby with another chromosomal abnormality was much higher. At 20, you have a one in 1,529 risk of having a Down’s syndrome child; at 40, the risk is one in 112.

I was offered – and accepted – a scan at the hospital where I was being monitored. In fact, I’d also given blood for testing, when suddenly the realisation of what I was doing hit me.

I sat in my consultant’s office with my new husband, and started to cry (yes, again). “I don’t want to do this,” I said. “I’m not going through that again – whatever the consequences.”

The consultant sent us away to have a coffee and talk the decision through, but my husband was already in agreement. There would be no termination. And therefore no need for testing. Simple. My blood samples were thrown away, and an entry confirming our decision was made on my case notes. I made my peace with my unborn baby: I would take what I was given.

About five months later, my daughter was born. She had no sign of chromosomal abnormalities. It dawned on me that once we had decided not to go ahead with tests for Down’s or anything else, I had stopped worrying about how our child would turn out. She was going to be our baby, and as long as she was born alive, everything else could be dealt with.

I’m not trying to underplay the enormous work and sacrifices that many families must undergo when they have a disabled child. And I’m certainly not sitting in judgment of families who do choose to terminate such a pregnancy and are at peace with their decision. I’m not against abortion per se, and never have been.

I worry nonetheless that there is a growing consensus that abortion should be the automatic choice when any foetus is diagnosed as less than “perfect”. It is an issue in desperate need of open debate. As for me, when the fear of losing another baby was weighed against the risk of disability, I knew where I stood.

Now aged 43, still desperate for that large family and still suffering miscarriages, I have to accept that I may never have another child. It’s very hard.

The ghost of my son lingers painfully, haunting my thoughts. In the past nine years, not a week has gone by when I haven’t thought of him. Despite the support that others – including those closest to me – expressed for my decision at the time, I don’t think I can ever truly forgive myself for what I did.

What I do know, and often think, is that if my son had been born alive and perhaps with two years to live, were those not two years of my life that I could have spared to nurse him? Would it really have been such a big deal? With hindsight, I think I could have offered that at the very least to a child I had wanted so much.

Bigger and better antenatal testing may thrill research scientists and be of enormous importance to those parents who are clear in their minds about the kinds of baby they want to bring into the world. For some of us, though, there is a grave danger that the very ease and simplicity of the tests make life-and- death decisions too easy to take – and to regret.

More information about the charity Antenatal Results and Choices can be found at www.arc-uk.org

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