I take a routine prenatal alpha-fetoprotein (AFP) test. The test measures the level of AFP produced by the foetus and present in the mother’s bloodstream.
It was designed to detect babies with rare neural tube defects such as spina bifida, as evidenced by a ‘high’ reading. Although the test wasn’t designed for it, low readings are now thought to be associated with an increased risk of Down’s syndrome.
‘Just to put your mind at rest,’ my doctor cajoled.
Since it only involved taking a blood sample from my upper arm rather than invading the womb as all other prenatal tests do, I let myself be talked into it. After all, I was having a fantastic pregnancy. I was convinced my baby was perfectly healthy. Now I’d know for sure. What was there to lose?
A week or so later, my doctor’s secretary rang and asked me to phone him. ‘What for? Did the test come back?’ I asked apprehensively.
‘That’s what he wants to discuss with you.’
For an agonizing half-hour I stayed on the phone waiting for him to get on the line. When he did, it was to report the words I’d never even thought to consider:‘The results of the AFP test are borderline low.’
I burst out in hysterical sobbing, and only after five minutes had calmed down sufficiently to ask what I already knew that meant.
‘There’s a slight possibility of Down’s syndrome.’
I don’t remember much of the rest of the conversation. My doctor tried a few gentle reassurances – we could find out for sure through a combination of amniocentesis and ultrasound; this combination of tests had a high degree of accuracy; the other borderline situations he’d investigated had turned out all right.
Finally I managed to say that I would call him back. I had a secretary drag my husband out of a meeting to tell him the news, and after he rushed home we considered our options. We could run through the battery of tests with ultrasound and amniocentesis, and risk miscarrying a perfectly healthy baby or damaging it through the test – both known risks of the procedure. We then discussed the ramifications of a test result confirming that I was carrying a handicapped child.
We would be faced with the decision of aborting a five-month-old foetus – not some lima-bean-sized tadpole, but a perfectly formed, nearly viable human being. It meant going through labour and giving birth to a dead baby or, if he wasn’t expelled in that manner, having the body removed, piece by piece.
I looked down at my bump. For me, that simply was not a possibility I could contemplate, no matter how deformed this child might be, which made the entire AFP exercise an utter waste of time. If you are not prepared to abort a handicapped foetus, there is no point in going through with the tests.
I was appalled by medicine at that moment for creating a situation that could only be resolved through the high-tech measures I had so wished to avoid. If I had never had the AFP test, I thought, I would never have had to consider subjecting my baby to a battery of possibly damaging tests just to bury the doubts raised by the first test result.
In the end, to our minds, there was only one reasonable path: to ignore the test and to listen to our hearts, which told us that the baby was fine.
This is what we chose to do. I called my doctor to tell him, and my husband and I never spoke about the test again. Sure enough, it turned out that we had been traumatized for nothing. The test was wrong. At the end of my term, out came our perfectly normal, healthy baby.
Despite the murmurs from your obstetrician about the very best in medical technology, most prenatal testing is little more than ritualistic nonsense.
ULTRASOUND SCANS
The mainstay of modern obstetric diagnosis is the ultrasound scan (or sonography) and is the most likely test you’ll be given, following hard at the heels of your urine test confirming pregnancy in the first place. Most women these days can show off pictures of their babies in the womb when they are not much past the tadpole stage. First developed during the Second World War to track down enemy submarines, ultrasound scanning began to be used in the 1970s for diagnostic testing and eventually for pregnancy.
Similar to radar, real-time scanners employ very-high-frequency pulsed sound waves (3.5–7 mHz, or 3.5–7 million cycles per second) that are sent to the foetus via a transducer placed on the abdomen. Echoes of the sound waves create moving images on the monitor screen.
In the radiology industries ultrasound is known as the biggest growth area, with equipment manufacturers enjoying a 20 per cent growth in sales over the next few years and some 60 to 90 million investigative tests of all sorts performed every year.1 Although originally planned to be used for aiding high-risk pregnancies, the exam is now presently looked upon, as New York’s Columbia University Professor Harold E. Fox once put it, as the equivalent of a ‘physical exam of the foetus in utero’,2 with a good reading the tacit assurance of a healthy baby. Virtually all pregnant women are now scanned and given photos or videos to take home as a pleasantly packaged souvenir of their first baby picture.
It’s meant to determine whether your baby is healthy and when you are likely to give birth. Scans supposedly can assess gestational age, size and growth, rule out multiple or tubal pregnancies or ovarian cysts, locate the position of the baby in the womb, and show whether the baby is growing properly or whether it has died.
A scan before 20 weeks also looks for abnormalities such as hydrocephalus, anencephaly, spina bifida, cleft lip or palate and congenital heart problems. Ultrasound is increasingly being used to pick up so-called ‘soft markers’ – subtle defects which may or may not be serious. It can identify club foot, low-set ears and even problems with facial development.
It is now the first port of call for checking for chromosomal abnormalities such as Down’s syndrome. At the bare minimum, women are scanned at 12, 18–20 and 34 weeks of pregnancy. Many are scanned 10 or 12 times before giving birth, starting as early as seven weeks into the pregnancy. In late pregnancy it is used to rule out placenta praevia, when a low-lying placenta blocks the birth passage.
Although doctors rely on scanning as an early warning signal of problems that can largely be remedied, babies who are scanned tend to have poorer outcomes, possibly because scans simply invite more invasive procedures that don’t appear to aid survival. In one study, more of the scanned babies died, were delivered sooner and spent more time in hospital and on ventilators than babies who were not scanned. Of those with abdominal wall defects, the scanned group were operated on sooner, but had the same outcomes as unscanned babies whose operations were delayed. Furthermore, more of the scanned babies died (23 per cent vs only 4 per cent of the unscanned babies).3 A German study found that caesarean section and preterm delivery was five times more frequent, and admission into intensive care three times higher, for babies diagnosed by ultrasound before birth.4
In the UK and the US, pregnant women are generally told by their doctors that ultrasound is as safe as a television set. The official line of the Royal College of Obstetricians and Gynaecologists is that the wave intensity currently used in scans is ‘probably’ safe. Obstetricians take the airy position that there are 50 million people walking around today who were scanned in the womb, and with no laboratory evidence to indicate that it is a hazard, they must be all right.
