The Pros and Cons of Growth Scans: Impact on Antenatal Care and Birth

Growth scans can be invaluable when there’s genuine clinical need—but in the UK, they’re sometimes over‑used, creating anxiety and influencing birth plans unnecessarily. We’re Vicky & Melissa from Beyond the Bump, here to help you navigate NICE’s antenatal care recommendations, understand when scans truly matter, and feel confident in your choices.

What Do NICE Guidelines Say?

According to the NICE NG201 antenatal care guideline:

Routine scan at 18–21 weeks: Anomaly scan is standard for all pregnancies.
Further growth scans only if indicated: Additional ultrasounds are recommended when there are specific risk factors (e.g., pre‑eclampsia, previous small‑for‑gestational‑age baby, diabetes) or worrying clinical signs (e.g., fundal height lagging).
No routine third‑trimester scans: Low‑risk women with normal history and examinations should not undergo extra growth scans, to avoid false positives and unnecessary interventions.

"Ensure scans are offered based on clinical need, not routine practice, to reduce over‑medicalisation and anxiety." (NICE NG201)

The Pros of Growth Scans—When They’re Really Needed

Targeted monitoring: For pregnancies at genuine risk (e.g., hypertension, diabetes), growth scans can spot small or large babies early, informing decisions on timing and mode of birth.
Preventing complications: Detecting growth restriction can lead to timely interventions—additional monitoring, changes in maternal position, or planned delivery—lowering stillbirth risk.
Reassurance in high‑risk scenarios: If you’ve experienced complications before, a scan provides tailored information and peace of mind.

The Cons of Unnecessary Scans

Increased anxiety: Measuring a baby who’s slightly under or over estimated can cause undue worry, and often resolves on its own as baby grows.
Unneeded interventions: Over‑estimation may lead to inductions or caesareans that carry their own risks and longer recovery.
Resource strain: NHS services are best reserved for clinically indicated scans; private scans can be expensive without clear benefit.

Making Informed Decisions

Discuss risk factors: At each antenatal appointment, ask your midwife about your risk profile—only then will additional scans be justified.
Track growth clinically: Fundal height measurements and checking how you feel often signal if further imaging is needed.
Ask about guidelines: If offered a private or extra scan, enquire how it aligns with NICE recommendations.

Use BRAIN for Informed Consent

Empower your decision-making by using the BRAIN approach:

Benefits: What good might come from this scan? (e.g., early detection of growth issues)
Risks: What could go wrong or cause worry? (e.g., false positives leading to unnecessary interventions)
Alternatives: What other ways can we monitor growth? (e.g., fundal height checks, Doppler)
Intuition: How do you feel about having the scan? Trust your instincts.
Nothing: What if you choose to wait and monitor clinically instead?