Pregnancy has a strange way of turning time into both a blur and an interrogation. Weeks pass quickly, yet every appointment can feel like a major event. At 24 weeks, an ultrasound scan offers one of the clearest windows into the small, developing world you have been carrying—part medical assessment, part emotional landmark, and part reminder that the human body is capable of astonishing work while demanding regular snacks.
A scan at this stage may be offered as a follow-up to the routine mid-pregnancy or anomaly scan, usually carried out between 18 and 21 weeks in the UK. Some people may have their detailed scan later because of scheduling, the baby’s position, limited visibility during the earlier appointment, or a need to monitor growth. The exact process varies between hospitals, clinics and countries, but the central purpose remains the same: to check development, measure growth and look for signs that additional care may be helpful.
Why might you have an ultrasound at 24 weeks?
The 24-week ultrasound is not always a standard appointment for every pregnancy. If you are offered one, your midwife or obstetrician should explain why. It may be arranged because the earlier anomaly scan could not capture all the required images, or because your healthcare team wants to monitor the baby more closely.
Common reasons include:
- The baby was in an awkward position during the previous scan.
- Some parts of the heart, brain or spine were difficult to view clearly.
- Your pregnancy is considered higher risk because of medical history or previous complications.
- There are concerns about the baby’s growth, fluid levels or placenta.
- You are expecting twins or multiples.
- Your dates are uncertain and growth needs to be assessed.
Sometimes the appointment is simply a repeat examination to obtain better images. This does not necessarily mean that anything is wrong. Ultrasound is a practical tool, not a crystal ball, and babies are remarkably talented at turning their backs precisely when someone needs to examine their spine.
What happens before the scan?
When you arrive, the sonographer or another trained professional will usually confirm your details, ask about your pregnancy and explain the examination. You should have an opportunity to ask questions before it begins. If you feel anxious, say so. Medical staff are accustomed to uncertainty, even if the person lying on the examination bed is experiencing it at full volume.
You may be asked to have a comfortably full bladder, particularly if the scan is being performed early in pregnancy or if your clinic has specific instructions. At 24 weeks, this is often less important because the uterus is large enough for the baby to be seen clearly, but follow the guidance provided by your hospital or clinic. Do not force yourself to drink excessive amounts of water; discomfort is not a badge of maternal commitment.
Wear clothing that allows easy access to your abdomen. You will normally remain fully dressed apart from exposing the area between your ribs and pelvis. A small amount of clear gel is placed on the skin. It can feel cold, although the sensation is brief.
What will the sonographer check?
The examination uses sound waves to create images of the baby, placenta and surrounding structures. It does not use X-rays. The sonographer moves a handheld device called a transducer across your abdomen, adjusting the angle and pressure to obtain different views.
At around 24 weeks, the scan may assess several aspects of your baby’s development, including:
- Head size and shape.
- Brain structures that can be viewed by ultrasound.
- Facial features, including the lips and profile.
- Spine and abdominal wall.
- Heart rate and, where possible, key views of the heart.
- Stomach, kidneys and bladder.
- Arms, legs, hands and feet.
- Overall growth and estimated weight.
- Position of the placenta.
- Amount of amniotic fluid.
Measurements are taken from different parts of the body, often including the head, abdomen and thigh bone. These figures are compared with expected ranges for the stage of pregnancy. They are estimates rather than precise predictions. A scan cannot tell you the baby’s exact weight, any more than standing on bathroom scales can reveal the precise mass of your thoughts, your lunch or the emotional burden of assembling flat-pack furniture.
How long does a 24-week ultrasound take?
A routine scan may take around 20 to 30 minutes, but the appointment can last longer if the baby is moving frequently, facing away or positioned in a way that makes certain structures difficult to see. The sonographer may ask you to turn on your side, walk around briefly or return after a short break.
It is common for the professional performing the scan to remain quiet for periods of time. This silence can feel ominous, especially when you are watching the screen and trying to decode shapes that resemble weather systems or abstract art. Usually, the sonographer is concentrating on obtaining accurate images and recording measurements. They may not be able to discuss findings while the scan is in progress, depending on local policy.
At the end, a doctor, midwife or sonographer may explain what has been seen and whether further appointments are needed. In some settings, the images are reviewed by another specialist before results are discussed. Ask when and how you will receive the report.
Can you see the baby’s face?
Possibly, although there are no guarantees. At 24 weeks, the baby’s features are more recognisable than earlier in pregnancy. You may see a profile, a hand near the face, a yawn or a small burst of movement. Three-dimensional or four-dimensional imaging may create more detailed pictures, but these are not always part of a medical scan and are not required to assess health.
The quality of the image depends on several factors, including the baby’s position, the amount of amniotic fluid, the location of the placenta and the thickness of the abdominal tissue. If the baby is facing your spine or hiding behind the placenta, the final image may be less cinematic than expected. This is not a reflection of the baby’s personality, although it may be an early sign of a strong instinct for privacy.
Will you find out the baby’s sex?
If you want to know, you can ask whether it is possible to identify the baby’s sex. Policies differ between hospitals and clinics, and identification may not be possible if the baby is in an unfavourable position. In the UK, the primary purpose of the scan is medical assessment, not sex determination.
Ultrasound cannot provide absolute certainty. If you would prefer not to know, tell the sonographer before the examination begins. This allows them to avoid mentioning it accidentally while describing the images.
What if the sonographer cannot see everything?
An incomplete scan does not automatically mean there is a problem. The baby may be curled up, moving constantly or positioned with its back facing outwards. Some structures are simply difficult to capture from a particular angle.
You may be invited back for another scan. This can be frustrating, especially if you have rearranged work, childcare or transport, but it usually means the clinical team wants better images rather than that they have identified an abnormality. Ask which views were incomplete and when the repeat appointment is likely to take place.
If a possible concern is identified, you should receive a clear explanation and information about what happens next. You may be referred to a specialist in fetal medicine for a more detailed scan or additional tests. A screening finding is not the same as a diagnosis. It indicates that further assessment may be useful; it does not write the final chapter.
What can the scan tell you about growth?
The measurements taken during the scan help the healthcare team assess whether the baby appears to be growing as expected. Growth charts are used to compare the estimated size with other babies at a similar stage of pregnancy. A result outside the average range does not necessarily indicate illness. Healthy babies come in different sizes, and family genetics play a role.
If growth appears slower or faster than expected, you may be offered additional monitoring. This might include repeat ultrasound scans, blood-flow measurements through the placenta and umbilical cord, or checks of your blood pressure and urine. The aim is to identify whether the placenta is working effectively and whether the baby needs closer observation.
It is worth remembering that estimated fetal weight has limitations. Ultrasound measurements can be affected by the baby’s position and by the mathematical formulas used to calculate weight. Numbers are helpful, but they are not destiny.
What about the placenta and amniotic fluid?
The sonographer will look at the placenta’s position and assess the amount of amniotic fluid around the baby. If the placenta is low-lying, it may be monitored later in pregnancy because its position can change as the uterus grows. A low placenta at 24 weeks does not automatically mean that a caesarean birth will be required.
The fluid surrounding the baby allows movement and supports development. Too much or too little fluid can have several possible causes, so an unusual finding would usually lead to further assessment rather than an immediate conclusion about what it means.
How might you feel during and after the scan?
Many people feel excitement, relief or wonder when they see the baby moving. Others feel detached, frightened or unexpectedly emotional. There is no correct response. Pregnancy does not turn every person into a serene figure in a flowing dress, gazing fondly at the horizon. Sometimes the dominant feeling is simply exhaustion.
If the scan brings difficult news, ask for time and support. You can request that information is repeated, written down or explained in simpler language. Consider bringing your partner, a trusted friend or another support person if the clinic allows it. You do not have to absorb every detail perfectly while processing fear.
After the scan, the gel is wiped away and you can usually return to normal activities immediately. Ultrasound does not generally cause pain, although the pressure of the transducer may feel uncomfortable, especially if your abdomen is tender or your bladder is full.
Questions worth asking at your appointment
- Was the baby’s growth consistent with the stage of pregnancy?
- Were all the required structures visible?
- Where is the placenta positioned?
- Was the amniotic fluid within the expected range?
- Do I need another scan or specialist appointment?
- When will I receive the written report?
- Who should I contact if I have questions afterwards?
Writing questions down beforehand can help. Pregnancy has a habit of making the simplest thought vanish the moment a medical professional asks, “Is there anything else you would like to know?”
When should you seek urgent medical advice?
The ultrasound appointment itself is not a substitute for maternity care. Contact your midwife, maternity unit or healthcare professional urgently if you experience heavy vaginal bleeding, severe abdominal pain, leaking fluid, regular painful contractions, a sudden severe headache, visual disturbances or swelling that appears rapidly.
At 24 weeks, movements may still vary from day to day, but you should become familiar with your baby’s usual pattern as pregnancy progresses. If you notice a reduction or change in movement, contact your maternity unit immediately rather than waiting for the next appointment. Do not rely on a home Doppler for reassurance; hearing a heartbeat does not confirm that everything is well.
A clearer picture, not a guarantee
A 24-week ultrasound can provide valuable information about development, growth, the placenta and the surrounding fluid. It may also offer a fleeting glimpse of a nose, a foot or a hand pressed against the uterine wall—small images with an unreasonable power to rearrange the heart.
But the scan has limits. It cannot detect every condition, predict every aspect of health or guarantee a particular birth experience. Its purpose is to gather useful evidence and guide appropriate care. If another scan or appointment is recommended, that is a continuation of the process, not a verdict.
For all its technology, the examination remains a meeting between uncertainty and attention: a trained professional looking carefully, a parent waiting, and a developing human being refusing to remain still for the photograph. That is pregnancy in miniature—measured in millimetres, experienced in emotions, and never quite as tidy as the timetable suggests.