Ultrasounds, Scans, Screenings and Tests
232As soon as you know you are pregnant, get in touch with your clinic or your doctor to organise your antenatal care. You can also find out about local antenatal classes, which will help you meet other women and prepare you for becoming a mum.
The basics of antenatal care
Find out how to start your antenatal care, and what to expect from your antenatal appointments.
Who's who in the antenatal team
Find out who does what in the antenatal team, including the doctor, sonographer and obstetrician.
Your first antenatal visit and booking appointment
Find out about the routine tests and information you'll be given, including healthy eating, and things the doctor might ask you.
Antenatal checks and tests you will be offered
Routine checks, such as blood pressure and urine tests, can give valuable information about your health at each antenatal appointment.
Preparing for antenatal appointments
Prepare any questions you might want to ask, and take snacks in case you have to wait.
Ultrasound scans
Find out how these routine scans are carried out and when you will be offered them.
Most hospitals will offer women at least two ultrasound scans during their pregnancy. The first is usually at around 8-14 weeks and is sometimes called the dating scan because it can help to determine when the baby is due. The second scan usually takes place between 18 and 20 weeks and is called the anomaly scan because it checks for structural abnormalities in the baby.
Ultrasound scans use sound waves to build a picture of the baby in the womb. The scans are completely painless, have no known side effects on mother or babies, and can be carried out at any stage of pregnancy. If you have any concerns about having a scan, talk to your doctor or obstetrician.
The anomaly scan
Find out about this scan, offered at 18-21 weeks, and how to prepare for it.
This is a detailed scan, usually carried out when you are 18-20 weeks pregnant, that checks for possible physical problems (abnormalities) in your baby, although it can't pick up every problem.
The scan is offered to all women, but not everyone chooses to have it. Your choice will be respected if you decide not to have the scan, and you'll be given the chance to discuss it with your maternity team before making your decision.
You may be asked to drink some fluid so that your bladder is full before you have the scan. A full bladder pushes your womb up and can give a clearer picture. You then lie on your back and some jelly is put on your abdomen. A probe is passed backwards and forwards over your skin and high-frequency sound is beamed through your abdomen into the womb. The sound is reflected back and creates a picture that's shown on a TV screen. Sometimes, the sonographer doing the scan will need to be quiet while they concentrate on checking your baby. However, they will be able to talk to you about the pictures once they've completed the check.
Most hospitals welcome partners into the scan room.
Tests for inherited disorders
Some conditions, such as sickle cell disorder and muscular dystrophy, are inherited. Find out how any risk to your baby can be worked out, and what the screening involves.
Some diseases or conditions are inherited from one or both parents. These include cystic fibrosis, haemophilia, muscular dystrophy, sickle cell disorders and thalassaemia. If you, your baby's father or any of your relatives has an inherited condition or if you already have a baby with a disability, talk to your doctor.
You may be able to have tests early in pregnancy to check whether your baby is at risk, or is affected. Ask your doctor to refer you to a genetic counsellor (a specialist in inherited diseases) for advice. Ideally, you should do this before you get pregnant or in the early weeks of pregnancy.
Tests to detect abnormalities
Find out about the scans and blood tests that can detect whether there is anything wrong with your baby.
You'll be offered screening tests that can detect structural abnormalities, such as spina bifida, which is a defect in the development of the spine, or some chromosomal disorders, such as Down's syndrome.
Different maternity units may use different tests, but all tests will meet national standards. You can discuss the tests and what they mean with your doctor.
Screening tests can:
- reassure you that your baby is likely to be born healthy,
- allow you to consider the termination of an affected baby, and
- give you time to prepare for the arrival of a baby with special needs.
Tests can also provide valuable information for your care during pregnancy. However, no test can guarantee that your baby will be born without an abnormality. Some abnormalities may be undetected before the birth.
When you're deciding whether or not to have a test, think about what you might do if the test suggests that your baby has an abnormality. If a screening test suggests a higher chance of a chromosomal abnormality, you'll be offered diagnostic tests, which will give a more definite diagnosis. These diagnostic tests carry a small risk of miscarriage, so you may decide not to have them. Discuss the issue with your partner, doctor, and friends to help you decide what's right for you.
The screening tests offered during pregnancy are either ultrasound scans or blood tests or a combination of both. Ultrasound scans may detect structural abnormalities, such as spina bifida. Blood tests and scans can help to detect chromosomal disorders, such as Down's syndrome.
Down's syndrome is caused by an abnormal number of chromosomes. Chromosomes are the structures within every cell of a person's body, which carry the individual genetic code or 'recipe' to make that person. Conditions such as sickle cell disease, thalassaemia, cystic fibrosis and achondroplasia (dwarfism) are caused by abnormalities within the chromosomes (i.e. a 'mistake' in the recipe).
See Related articles for more information on screening for Down's syndrome and the anomaly scan, which you'll be offered at 18-21 weeks.





