For many women, ultrasounds may be the first time you've had a scan. Here's our guide on what to expect.
Ultrasounds
In many ways, ultrasound tests are the most stress-free of pregnancy testing: they pose no risk to you or your baby, they are completely painless, plus you get to see what your baby looks like.
They work by constructing images of inside and around your uterus using echoes of sound waves.
Basic Ultrasound – The first view
If your scan is taking place in the first 12 weeks, an ultrasound image will be made by placing a small probe in your vagina. Early ultrasounds are very good for calculating your due date and the week of conception.
News on baby The scans also check your baby's well being and look for any abnormalities present. Things that will be looked at include your baby's heartbeat, its developing anatomy and its location. If you are carrying twins (or more!) this scan will alert you.
News on you This ultrasound will also check your well-being. Ovarian cysts can be detected at this stage and the test will also look at how your uterus and cervix are doing and whether you have an ectopic pregnancy – which if left undetected could put your life at risk.
Say Hello The nicest part of the ultrasound is that you can usually see your baby's face in this scan, but don't be alarmed if it looks more like a skull! You usually get a good idea of the baby’s gender at this stage if baby lets you get a look. Some babies are camera shy.
Anomaly ultrasound You can expect a more detailed ultrasound between 16 and 22 weeks. During this procedure, lots of measurements will be taken of your baby's body. These will be of its brain, skull, heart, chest cavity, diaphragm, abdominal cavity and walls, stomach, kidneys, bladder, arms, legs and spine: phew!
Detecting problems Although this scan can’t diagnose every single defect, it can alert the doctor to potential problems that need further checking out. If this happens you will be booked in for further tests such as Chorionic Villus Sampling (CVS) or amniocentesis.
Further ultrasounds These are not a matter of routine, but in some cases you might be asked back for additional scanning. Reasons for this include you carrying twins or more, your baby seeming to be too small or too large, or if there’s uncertainty over whether you are carrying the right amount of amniotic fluid. You also may need further screening if you run the risk of premature labour, if you are losing blood or have existing health conditions such as diabetes or hypertension.
Nuchal Translucency Screening These are specialist ultrasounds designed to measure a fluid filled area behind your baby's neck called the nuchal translucency. Eighty per cent of cases of Down's Syndrome are identified in this way.
A matter of routine Some hospitals and clinics will offer you one of these scans as a matter of routine at 11-13 weeks. They can then work out the risk of genetic abnormality in your baby based on your age and the size of your baby’s nuchal translucency.
Weighing up the risks If you are rated as high risk, you will be offered further tests such as amniocentesis or CVS. Try not to worry if this happens as many high risk cases are false alarms.
For many women, ultrasounds may be the first time you've had a scan. Here's our guide on what to expect. 
