Growth Scan in Pregnancy

This information leaflet has been produced by Gateshead Health NHS Foundation Trust Maternity Unit to provide information to pregnant women who are recommended to have one or multiple growth scans in pregnancy.

What is the purpose of a growth scan?

A growth scan, or 3rd trimester scan, can take place at any time between 24 and 41 weeks gestation. The sonographer will take several measurements which will give us a representation of your baby’s wellbeing. Assessing these factors can tell us if a baby is growing well or may need further intervention.

Who has growth scans?

You may be referred for a series of growth scans during your pregnancy if you are identified as being ‘moderate’ or ‘high’ risk in your pregnancy. These scans will be requested 1 at a time when you are seen by the doctor in Women’s Health Clinic (WHC) and you will be able to see the appointments on the Badger Notes App and via an appointments letter that will be sent by post.

Cartoon Ultrasound scan machine and sonographer

Urgent Growth scans are sometimes required for the following reasons:

  • Recurrent episodes of reduced fetal movements
  • Diagnosis of a medical condition
  • Slowing measurement or small measurement when the midwife measures the symphysis fundal height (the measurement of your bump)
  • Slowing growth on a serial growth scan

There are many conditions that may require referral for a growth scan, your midwife or doctor will discuss this with you if we identify a risk factor. The appointments will be seen on your Badger Notes App or may be telephoned out if they are appointed more urgently.

Preparing for your growth scan

We ask you to come for your growth scan with a full bladder. You should drink a pint of water approximately an hour before your appointment time.
Please also remove any belly button bars or rings as these may damage the ultrasound equipment.

You may bring a support person to the scan appointment who can come into the exam room with you. We ask you do not bring children to the hospital unless absolutely necessary. Your support person may be asked to wait outside with the child if this situation occurs.

During the growth scan

The scan will take approximately 20-30 minutes. During the scan, the following will be completed:

  • Measurements of head, abdomen, and femur length (the bone of the thigh) which generate an estimated weight of your baby at that time
  • An estimate of the liquor volume (amniotic fluid) around your baby
  • An assessment of the blood flow moving from your placenta to your baby, known as an umbilical artery doppler
  • A general overview of your baby

At the end of the scan, the sonographer will plot the estimated weight (EFW) of your baby on the electronic chart (Intergrowth 21st Chart). This will tell us if your baby’s weight and the pattern of growth is perceived to be normal for you.

What if your baby’s weight is small or slowing of growth is found?

If the growth of your baby is slowing down or your baby measures below the 10th centile or above the 97th on your GROW chart, you may need some extra scans and appointments to keep a closer eye on your pregnancy. Your scan will be reviewed by the doctors either in the Women’s Health Clinic (WHC), Pregnancy Assessment Unit (PAU) or by telephone (after a referral is sent by the sonographer) to make an individualised plan for your pregnancy.

Increased Umbilical Artery Doppler Measurement

Sometimes, we find the placenta is working harder to push blood along the cord to oxygenate your baby, you may hear this being referred to as ‘raised PI’. In these cases, we have to monitor you very closely to ensure the growth of your baby is normal, the placenta is still functioning and that baby’s oxygen supply is adequate. You will have intensive input from the medical team to time these scans appropriately and also make recommendations about your pregnancy and birth. It is very important to contact Pregnancy Assessment Unit (PAU) if you have any concerns about your baby’s movements or pattern of movements if you have an increased PI.

Do I still need to call the hospital with reduced fetal movements if I am having scans?

YES!

It is imperative that you call PAU immediately if you have any concerns about the pattern of your baby’s movements or feel the movements are reduced. While an ultrasound scan can give reassurance at the time of the scan, we still need to assess your baby’s heartbeat. We can do this by using a machine called a cardiotocograph, often referred to as a ‘CTG’. You are typically on this for 20-60 minutes which allows the midwives or doctors to observe several features of a baby’s heart rate to ensure it is normal and there are no signs of distress. You should even call PAU if you have concerns about movements and have or have had a scan the same day.

Useful sources of information

Photographs of your ultrasound scan can be purchased via contactless payment in the pregnancy assessment unit and women’s health clinic. While every effort is made to give you a good image, sometimes it isn’t possible due to the position of the baby.
Video equipment is not to be used under any circumstances in the scan room. We ask that all phones are turned off for the duration of the exam.

Contact number

Pregnancy Assessment Unit: 0191 445 2764

Community Midwives: 0191 445 2140

Appointments line: 0191 445 2718

If you need to cancel or re-arrange your appointment, please contact our appointments line between 8am – 8pm, Monday-Friday, so that we are able to offer this appointment to another patient.

Maternity

Gateshead Health NHS Foundation Trust

Queen Elizabeth Hospital,

Queen Elizabeth Avenue,

Sheriff Hill,

Gateshead,

NE9 6SX