What is an anomaly scan?
An anomaly scan is a detailed ultrasound carried out during pregnancy to check your baby’s development. Also known as the mid-pregnancy scan or 20-week scan, it gives your sonographer a thorough look at how your baby is growing and whether all the major organs are forming as expected.
For most women, this scan brings enormous reassurance. For some, it raises questions that need careful follow-up. Either way, it’s one of the most important appointments in your pregnancy.
Expecting your 20-week scan? Book a private anomaly scan at Ovara Health →
When is the anomaly scan done?
The anomaly scan is typically carried out between 18 and 22 weeks of pregnancy. The NHS recommends 20 weeks as the standard timing, and most private clinics follow the same guidance.
At this stage, your baby is developed enough for the sonographer to get a clear view of all the structures they need to assess.
Before 18 weeks, some organs may not yet be fully visible but after 22 weeks, the baby’s size can make certain checks more difficult.
If your baby’s position limits visibility during the scan, you may be invited back for a repeat scan to ensure nothing is missed.
What does the anomaly scan check?
The sonographer will systematically examine your baby’s anatomy, including:
- Head and brain – checking the skull shape and brain development
- Face – looking for any cleft lip
- Spine – assessing that the vertebrae are aligned and the skin covers the spine
- Heart – checking the four chambers and major vessels
- Stomach and abdominal wall – ensuring the digestive system is developing correctly
- Kidneys – checking both are present and functioning
- Limbs – counting fingers and toes and checking bone development
- Placenta position – identifying any low-lying placenta that may need monitoring
- Amniotic fluid levels – ensuring there is the right amount of fluid around the baby
The scan also records your baby’s measurements to check they are growing in line with their gestational age.
Can the anomaly scan tell the babys gender?
The primary purpose of the scan is medical however, if your baby is in a good position and you’d like to know, the sonographer may be able to tell you the sex – this isn’t always guaranteed however as it depends on how your baby is lying at the time of the scanning.
What happens if something is found?
The majority of anomaly scans show that everything is developing normally. However, in some cases the sonographer may identify something that needs further investigation.
This doesn’t always mean there is a serious problem — sometimes a finding simply requires closer monitoring in subsequent scans. If a concern is identified, your consultant will explain the findings clearly and calmly, and discuss what the next steps look like.
At Ovara Health, our consultants are experienced in supporting women through every outcome, and you will never be left without a clear plan or someone to speak to.
Have questions about your scan results or need a 2nd opinion? If so get in touch with us here →
Can I have a private anomaly scan?
Yes – many women choose a private anomaly scan for a number of reasons:
- A more relaxed appointment / environment
- A longer scan time
- The ability to have partners / family members present
- Greater peave of mind with access to a Specialist Sonographer
At Ovara Health in Fulham London, our sonographers provide detailed, expert-led anomaly scans in a calm and comfortable environment.
You’ll receive your results during your appointment and have the opportunity to ask any questions.
Book your private anomaly scan at Ovara Health →
Frequently Asked Questions
Does the anomaly scan hurt?
No – like all ultrasound scans, the anomaly scan is non-invasive and painless. A small amount of gel is applied to your abdomen and the sonographer moves a probe gently across your skin to capture images.
Do I need a full bladder for the anomaly scan?
At 20 weeks, a full bladder is generally not required – your baby is large enough to scan clearly without one. However, it’s always a good idea to check with your clinic beforehand as guidance can vary slightly.
How long does the anomaly scan take?
Most anomaly scans last between 30 and 45 minutes, though this can vary depending on your baby’s position and how clearly the sonographer can see each structure.
What if my baby won’t co-operate during the scan?
If your baby is in an awkward position, the sonographer may ask you to move around, take a short walk, or have a small snack to encourage movement. In some cases, a follow-up appointment is offered to complete the assessment.
Is the anomaly scan available on the NHS?
Yes — the anomaly scan is offered routinely on the NHS as part of antenatal care. Private scans are also available for those who prefer a more personalised experience or a sooner appointment.