Can anyone accompany me for the scans?
Yes definitely! The scans are part of the life changing experience of having a baby, so taking your partner, close friend or family member along is a real must.
How do Ultrasounds work and how are they carried out?
An ultrasound scan uses high-frequency sound waves, which bounce off solid objects. This creates a screen image of your uterus and nearby organs, as well as your baby, the baby's organs and the placenta.
While you're lying down, the operator (usually a sonographer or radiographer) spreads gel over your tummy and rolls a hand-held transducer across the area. The images are transmitted to a screen. These may be printed out and a copy kept with your notes. You may also be given a print, although you may have to pay for this.
There is no strong evidence to suggest that ultrasound harm babies. There is a small amount of research that suggests a few babies could be affected and therefore some people think that more long-term research needs to be done in order to make ultrasound safer, but others feel it is so widely used that any serious problems would have shown up by now.
In terms of accuracy in detecting problems with your baby, scanning depends on a number of factors from the way your baby is lying, to the quality of the ultrasound machine being used, but most importantly the training and skill of the person undertaking the scan!
Can I find out my baby’s sex?
It's often possible to tell the sex of your baby at the 18-22 week scan. You might be asked if you want to know, but some hospitals have a non-disclosure policy. Remember it's not 100 per cent reliable and there are tales of parents being caught out with a nursery not quite being the correct colour match!
What can the scans pick up?
Depending on the type of scan you are having, the results may be diagnostic - it could show, for example, that your baby's brain hasn't formed properly (anencephaly) or that he has a gap in his spine (spina bifida). However, your scan is much more likely to act as a screening test which means that it may provide some evidence of developmental or medical problems that need further investigation.
If your scan suggests there is a problem with your baby, it's important to ask how serious the problem is likely to be, whether there are better scanning techniques at your hospital, (for instance MRI), that could be used to give a more accurate diagnosis.
The sonographer at your anomaly scan will also check the position, size and function of the placenta that supplies your baby with blood (and oxygen) plus nutrients from your own body. If your placenta is low-lying, i.e. across or near to the neck of the womb, you will be offered another scan later on in pregnancy to see if it has moved - the most likely outcome - in which case it won't present any further problems. If the placenta continues to block the womb, you'll be booked in for a caesarean section around your due date.
Doppler scanning uses black and white or colour images to trace the blood flow between the placenta and your baby through the umbilical cord. Using colour allows the sonographer to identify more easily the various different blood vessels. If needed, doppler scanning can usually be done during the anomaly scan, as long as the hospital's equipment is up to speed, and may be used at regular intervals throughout the pregnancy to keep a check on any known placental problems.
If your baby doesn't grow at the expected rate and is thought to be 'small for dates', you may also be offered doppler scanning as having a small baby could indicate placental problems. Doppler can also be used to predict your risk of pre-eclampsia, the high blood pressure disease of pregnancy, so that early preventive treatment can be given.
Down’s screening test
The nuchal fold translucency test is the latest and most accurate screening test for Down's Syndrome. It uses ultrasound to measure the amount of fluid between two layers of skin behind your baby's neck as those with Down's have a great collection of fluid than those who don't. This measurement is then fed into a computer, along with your age (the risk of Down's increases naturally with age), your baby's heart rate and any blood test results. The result will give you a risk factor, for example, one in 400, of having a baby with Down's and it's then up to you to decide whether to go on and have a diagnostic test such as amniocentesis. Additionally, the ultrasound can be used to check for the absence of a nasal bone, as this can be a potential sign of Down’s being present.
Only 10 per cent of women are offered the nuchal scan on the NHS (this is rising, with Kettering General Hospital being one of the latest to include nuchal scans as part of the standard screening) but it is available privately across the country with fees ranging from £90-£150.
3D/4D scans
Various manufacturers of ultrasound equipment, universities and private clinics are developing 3D technology with ultrasound and it is now widely available. The term 3D means that a life-like picture of your baby can be built from images of the three 'planes' of vision that make up 3D, stored on the computer after the ultrasound, while 4D refers to a moving 3D image. The ultrasound takes the same as a conventional scan because the images are recorded simultaneously. Experts using 3D/4D scanning say this 'surface reconstruction' is faster and gives a clearer image of the baby's external anatomy including the face, hands and feet as well as the baby's activity in the womb. However, a well-trained sonographer should pick up any problems using conventional 2D technology
