Ultrasound baby scans in pregnancy

Trish Chudleigh

Lead Sonographer and Advanced Practitioner Manager
Trish Chudleigh
All women are offered ultrasound examinations (scans) during their pregnancy to provide an estimated date of delivery, to see if they are having more than one baby and also to detect any problems.

Last year, our sonographers at the Rosie hospital performed 22,000 scans. In order to meet the demand for scans the clinic has a tight appointment schedule and it is therefore very important that you arrive in time. If you arrive late, we may not be able to scan you and may have to reschedule your appointment.

The dating scan and detailed anomaly scan are offered to all women, but you don't have to accept them. Your choice will be respected if you decide not to have the scans, and you'll be given the chance to discuss it with your maternity team before making your decision.

Dating scan

The dating and/or nuchal translucency scan is the first routine scan.

This first routine scan is carried out for the following reasons:

  • to confirm when the baby is due:
    the early scan helps us to work out the date when your baby is due. We might suggest a different date from that indicated by your last period. This is because not all pregnancies are conceived exactly 14 days after the first day of the last period. If your pregnancy is the result of assisted conception, we would normally calculate the delivery date from the date of your treatment. It is important to know your final due date for your care later in pregnancy.
  • to see if you are expecting more than one baby:
    most families would like to know if twins are expected to help them to plan ahead. It is also important to help us to plan your care appropriately. If we find that you are expecting twins, this is the best time to determine whether this is a dichorionic (non-identical) or monochorionic (identical) twin pregnancy.
  • to confirm the baby’s heart is beating
  • to detect problems of development that can sometimes be seen at this early stage
  • to detect other problems such as ovarian cysts (in you, not your baby)
  • to perform combined screening for Down’s syndrome if this is what you wish

Since November 2010, the Rosie hospital has offered all women screening for Down’s syndrome at their first routine scan. This is known as ‘combined screening’ because it involves an ultrasound scan (the ‘nuchal translucency scan’) and a blood test. The optimum time for the nuchal translucency scan to be performed is around 12 weeks but it can only be performed between 11 weeks and 2 days and 14 weeks and 1 day.

As with all tests in pregnancy, combined screening for Down’s syndrome is optional. It is not diagnostic. This means that the screening will only identify a baby as being at a ‘high’ or ‘low risk’ of being affected by Down’s syndrome. The screening will not definitely determine whether a baby does or does not have Down’s syndrome. Women who are identified as ‘high risk’ will be contacted directly and offered further testing.

If you do not wish to have combined screening for Down’s syndrome, you will be offered a dating scan. We also like to arrange this for around 12 weeks, but it can be performed between 10 and 14 weeks.

Sometimes, it is not possible to take measurements of the nuchal translucency. In this case, you will be offered the quadruple test (a blood test which can be performed between 14 weeks and 20 weeks + 6 days) as your screening test for Down’s syndrome.

Occasionally during the scan, a miscarriage might be diagnosed even though you might still 'feel pregnant'. In this case, the sonographer (the person who does the scan) will discuss the scan findings with you and arrange for a doctor to see you.

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Detailed scan

All women are offered a detailed or 'anomaly' scan between 18 weeks and 0 days and 20 weeks and 6 days. It's called the anomaly scan because it checks for structural abnormalities (anomalies) in the baby.

We screen for 11 specific conditions in accordance with the fetal anomaly screening programme:

  • Anencephaly
  • Spina bifida
  • Cleft lip
  • Diaphragmatic hernia
  • Gastroschisis
  • Exomphalos
  • Seven serious cardiac abnormalities
  • Bilateral renal agenesis
  • Lethal skeletal dysplasia
  • Edwards' syndrome (Trisomy 18)
  • Patau's syndrome (Trisomy 13)

The scan will also check the position of the placenta.

Ultrasound findings which are not normal

For the majority of women, the 18-20 week scan is a reassuring and memorable experience, but sometimes problems are found. If any abnormalities are detected during the scan the sonographer will discuss these with you and arrange for you to see a fetal medicine midwife or doctor at the earliest opportunity.

Some findings may not be significant and will resolve themselves. Others can forewarn of problems that would otherwise not be detected until birth or even infancy. Some information can cause considerable anxiety and can lead parents to consider options regarding continuation of the pregnancy.

It must be remembered that a normal scan does not guarantee fetal health and well being.

It is important to remember that only some abnormalities can be detected by scan; others are difficult to detect and therefore may be overlooked by scan, while some do not develop until later in the pregnancy or after birth.

Further scans

Women with diabetes, twins or other specific clinical indications will be offered additional scans, the number of which will depend on their specific situation.

These will be discussed at antenatal clinic appointments. Further scans may also be offered to other women depending on their history/concerns regarding their pregnancy.

Growth scan

If your doctor or midwife is concerned about the baby’s growth, an additional scan will be requested and will be arranged by the scan department. At this time, the sonographer will measure the baby’s size and the amount of fluid around the baby.

Placental localisation scan

If the position of the placenta is close to the birth canal, we will ask you to return at 32 or 36 weeks to check its position again. Depending on where the placenta is, we may need to perform a transvaginal (internal) scan to see the edge of the placenta correctly. If it is still low, we will arrange for you to see a doctor. Normally, the placenta will move away from the lower part of the uterus (womb) and the birth canal as pregnancy progresses.

Uterine artery Doppler scan

This is a scan which measures the blood flow from your uterus to the placenta and is done at 22-24 weeks. This blood flow measurement helps us to predict how well the placenta will function towards the end of pregnancy. If the uterine artery Doppler scan shows that the placenta may not work so well towards the end of pregnancy, we will monitor you and the baby closely throughout the remainder of the pregnancy.

Cervical length scan

This is an internal scan which is performed between 16 and 22 weeks and is requested for women who have had previous cervical surgery and/or mid pregnancy losses.

The scan report

You will be given a written report of the scan findings after every scan. You should keep this report in your handheld maternity notes. We also keep a copy in your hospital notes. If you have any queries either during the scan or afterwards, please ask your sonographer as we would wish to resolve any anxieties as soon as possible.

Department - Ultrasound

All women booking for delivery at the Rosie are offered two ultrasound examinations ('scans') during their pregnancy. The first is to provide an estimated date of delivery and to see how many babies are present. The second is to check the baby's anatomy. All women are also offered a screening test for Down's syndrome.
Opening times: 

Monday to Friday 09:00 – 16:00

01223 217 621

Trish Chudleigh

Lead Sonographer and Advanced Practitioner Manager
Trish Chudleigh

For many women, ultrasound scans are the highlight of pregnancy. It's very exciting and moving to 'see' your baby in the womb, often moving his or her hands and legs. The sonographer will ask you to lie on your back and she or he will put some lubricating gel on your abdomen. A small device is then 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, which is shown on a TV screen. The scans are completely painless and have no known side effects on mothers or babies.

Your partner is welcome to join you in the scan room, but as the scan is an important clinical investigation which requires maximum concentration, we would suggest that you please make arrangements for childcare. We would also appreciate it if you/your partner do not bring food and/or drink into the scan room.

You do not need a full bladder for any of our scans.

If you want to find out the sex of your baby, you can usually do so during the detailed anomaly scan. Tell the sonographer that you'd like to know your baby's sex at the start of the scan. Be aware though, that it's not always possible for the sonographer to be 100% certain about your baby's sex. For example, if your baby is lying in an awkward position, it may be difficult or impossible to tell whether your baby is male or female.

Your scan is an important medical examination and it is essential that our sonographers are allowed to concentrate fully without the distraction of filming. Therefore the use of mobile phone cameras, videos and other photographic equipment is not allowed during your ultrasound scan.

If you would like to keep a copy of your scan images, we are able to sell you pictures:

  • £6 - one picture
  • £12 - three pictures
  • £15 - four pictures
  • £20 - six pictures

Please ensure you bring the correct money as we are unable to provide change.

Thank you for your co-operation and understanding.

Finding us: 

The ultrasound department is on the ground floor of the Rosie hospital, next to clinic 24 and opposite clinic 21; Rosie outpatients. Head straight through the Rosie reception area, past the Pavilion cafe and follow the signs to the ultrasound department, which is on the left.

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