Fear played no part in the first nineteen weeks of my second? pregnancy. When Daniel was conceived I was fit and feeling great - I had recently? trained for and competed in a half marathon, my diet was largely organic, and I? had taken all the recommended pre-pregnancy supplements - so from the moment I? saw the second thin blue line on my home pregnancy test, I was confident I? would deliver a healthy baby come July the following year.

When at almost fourteen weeks I was offered maternal serum? screening (MSS) I declined, largely because I understood that it could not? produce a definitive result. The purpose of MSS is to identify babies at higher? risk of Down syndrome, anencephaly and spina bifida, but it cannot confirm or? rule out the presence of these congenital problems. Instead it returns an? 'estimation of risk' and, if this is greater than 1 in 250, further screening? is offered, usually in the form of a nuchal translucency scan.

As both MSS and nuchal translucency return a percentage of? 'false positives' and 'false negatives', some babies assessed to be at higher? risk will turn out not to be affected, while others deemed to be low risk will? be born with the targeted congenital abnormalities. It was too late in my? pregnancy for nuchal translucency to deliver accurate results so, for me, the? next step would be amniocentesis, an invasive diagnostic test carrying a? 1-in-200 risk of miscarriage.?

At thirty-seven, my risk for Down syndrome was already? 1-in-242, but I was not convinced it would benefit me to know of such an? outcome in advance. Paul and I felt strongly that we would be able to accept? and love our baby irrespective of any disability and saw no point in undergoing? early testing which would not alter the outcome of my pregnancy, regardless of? what it revealed. For these same reasons I initially considered forgoing the? recommended prenatal ultrasound at nineteen weeks. Ultimately and, as it turned? out, somewhat ironically, I consented to proceed for peace of mind. I had? planned to give birth at home and an ultrasound, I thought at the time, would? rule out some of the more obvious problems that might hinder a safe home? delivery. I had never heard of ultrasound markers, and did not understand what? they might mean. I certainly knew nothing of the myriad of congenital disorders? to which I would soon be suddenly and shockingly introduced.

Prenatal ultrasound has become such an established and? widely sanctioned facet of the contemporary woman's pregnancy that the vast? majority of mothers-to-be undergo at least one and, more commonly, multiple? scans. But how many of us, as? we dutifully report at the twelve- or eighteen-week mark or eagerly request? more regular glimpses of what lies beneath, appreciate the capabilities,? limitations and risks of this technology we have so readily accepted as a? fundamental part of the antenatal experience? How many mothers-to-be, as they lie,? bulging bellies exposed, staring wide-eyed at the fuzzy pictures before them,? are really aware of what those images might reveal or, as importantly, what? they might not?

According? to Monica Rafie, founder of BeNotAfraid.net, a support web site for families? receiving a poor prenatal diagnosis, many women are reluctant to undergo? prenatal screening but assume that the benefits of proceeding will outweigh? their reservations. 'They are not always informed,' she suggests, 'that from a? medical perspective, the primary purpose of this prenatal screening has less to? do with improving or ensuring [the] health of the baby, and more to do with? identifying babies at higher risk of syndromes or congenital malformations as? early as possible (2006).'

Internationally? published advocate for gentle birth, Dr Sarah Buckley, shares Rafie's concerns.

'... [women's] experiences and? wishes are presumed to coincide with, or be less important than, the medical? information that ultrasound provides. For example, supporters of RPU [routine? prenatal ultrasound] presume that early diagnosis is beneficial to the? affected woman and her family. However the discovery of a major abnormality on? RPU can lead to very difficult decision-making. Some women who agree to have an? ultrasound are unaware that they may get information about their baby that they? do not want, as they would not contemplate a termination (2005).'