4D Baby Scans: A Question of Safety
We have had ultrasound as a diagnostic medical tool for over 60 years now. In pregnancy care, it has been mainstream for almost 40 years. Because of its ubiquity, the issue of safety of traditional ultrasound is settled. People know that this test will not harm the baby. That belief is based on fact and solid scientific evidence. Ultrasound is, in essence, sound waves produced at very high frequency. The sound is not perceptible to the human ear. Images are formed dependent on how the sound waves bounce off the various structures. What is important to stress is that ultrasound as a technology does not involve any ionizing radiation.
Touch the emotions
4D ultrasound is relatively new. It found widespread use only in the last decade. It has become rapidly popular as a ‘bonding’ tool in pregnancy. Many prospective parents find the experience deeply affecting. Whilst traditional 2-dimensional (2D) ultrasound images can be difficult to make out for an untrained eye, 4D scan images show the baby as close to real life as you ca possibly imagine. The prospective parents can make out the activities of the baby in the womb sometimes with astonishing clarity particularly so when performed in the optimal window stretching from 24 to 32 weeks. It is, of course, possible to perform this at any stage of pregnancy but the experience is unlikely to be as good earlier as the baby is arguably too small. After 32 weeks, there is reduced room and therefore reduced fetal movements. You may see the facial gestures but not so much the gymnastics.
3D or 4D?
The label '4D' does sometimes create confusion. The explanation is simple. Still images are three dimensional [3D] (as opposed to the conventional two-dimensional images). Because with scanning the images are dynamic, rather than static, the term 4D or 4-dimensional has been adopted; the movements being the fourth dimension. In other words, these are moving 3D images.
2D Scan: 20 weeks
3D Scan Image
4D scan is Safe
What any user of the technology needs to know when it comes to safety is that, the technology is exactly the same as the long-standing 2D ultrasound. The difference is the computing power and the software applied to generate the images. 4D as would be expected utilises much more computing power. Whilst the technology has been available in research settings since the early 1990s, it has, so far, not been economically viable in a general hospital setting to have this. Thanks to rapid progress in computer technology, this is no longer the case. Man landed on the moon in 1969. That’s just over 40 years ago only. It is actually not an exaggeration when it is said that there is more computing power in your standard Smartphone today than there was in the Apollo 11 module. Such has been the astonishing stride in computing. What was unachievable only a decade ago is now taken as standard. Medicine has, indeed, been one of the beneficiaries.
Technology used being the same; the issue of safety has not changed. 4D scans are as safe for mother and baby as traditional 2D scans.
The use of ultrasound does cause an elevation of temperature in the tissues where it is applied. This occurs very gradually and it would take a very prolonged session to have any appreciable rise. Evidence shows that an elevation of 1.5°C is perfectly safe even in a prolonged scan session. Users can be reassured in knowing that this level of temperature elevation is very rarely reached. What’s more, modern ultrasound machines have what is known as a Thermal Index (TI) which continually tells the operator the temperature changes in the tissue. This allows the operator to curtail the session if there was an elevation towards a level that is considered potentially unsafe. Such a development is exceptionally rare.
In pregnancy care, 4D scan images do certainly look dramatically realistic, a far cry from the grey and white shadows that can characterise the traditional 2D scan image, especially in late pregnancy. There is no question that the availability of this technology has enhanced the involvement of the mother in what is going on inside her womb during this uniquely momentous time in her life. You can call it bonding or any other name but it is clearly a window into what has, hitherto, been felt but unseen. Medically, 4D baby ultrasound does not offer any advantage over conventional 2D scan in its diagnostic role. That may change in the course of time. As things stand, 4D scan has to be looked at as a safe social (rather than medical) tool, meant to enhance the mother’s/parents’ pregnancy experience.