Gender Scan: Complete Guide
Complete guide to private gender scans in the UK. When, cost, and accuracy.
Finding out your baby's sex is one of the most exciting milestones of pregnancy, but the NHS route and the private route work quite differently. This guide walks through when you can find out, what a private gender scan involves, and how it compares to what's offered on the NHS.
NHS vs private gender scans
On the NHS, sex is not guaranteed to be checked or disclosed at any scan — it depends on your local trust's policy. Where it is offered, it's usually at the 18-21 week anomaly scan, and the sonographer will only tell you if the baby is in a good position and you specifically ask. Some trusts have a policy of not disclosing sex at all, so it's worth checking with your hospital in advance if this matters to you.
Private clinics, by contrast, exist specifically to offer this information, often much earlier than the NHS anomaly scan:
- Nub theory scans (from around 12-13 weeks) look at the angle of a small nub visible near the base of the spine. This is genuinely a recognised technique used by trained sonographers, though it is less reliable than later scans and works best as part of a combined assessment rather than on its own.
- Dedicated gender scans (from around 16 weeks) look directly at the genitalia and are considerably more reliable once the baby is in a good viewing position.
- Blood tests (such as NIPT/SneakPeek-style tests, from around 9-10 weeks) analyse fetal DNA in the mother's blood and can be highly accurate, though they are a separate service from an ultrasound scan and come at their own cost.
What to expect at the appointment
A private gender scan typically takes 15-30 minutes. The sonographer will check the baby's position first — if the baby is curled up or facing away, they may ask you to move around, cough, or come back later in the appointment to try again. A full bladder in earlier scans can sometimes help push the uterus into a better position for viewing, so check your clinic's advice beforehand. Most clinics provide printed or digital photos, and many offer a sealed envelope or "gender reveal" option if you want to keep the result private for a reveal party.
Choosing a clinic
- Check the clinic is registered with the Care Quality Commission (CQC) in England, or the equivalent regulator in Scotland, Wales, or Northern Ireland.
- Ask whether the sonographer is qualified and what happens if the baby's position makes the sex unclear on the day.
- Confirm whether a rescan is included free of charge if the result is inconclusive.
Frequently Asked Questions
How early can I find out my baby's sex?
The earliest options are blood-based tests from around 9-10 weeks, followed by nub theory scans from around 12-13 weeks, and dedicated ultrasound gender scans from around 16 weeks. Accuracy generally improves the later you go, because the baby is bigger and easier to see clearly.
Is a private gender scan accurate?
Accuracy varies by method and by how well-positioned the baby is on the day. Later scans (16 weeks+) that directly view the genitalia tend to be more reliable than earlier techniques. No method is 100% guaranteed, which is why many clinics offer a free rescan if the result was unclear.
Will the NHS tell me my baby's sex?
It depends on your local trust's policy — some will confirm sex at the 18-21 week anomaly scan if you ask and the baby is well-positioned, while others don't disclose it as a matter of policy. Ask your midwife or hospital directly to find out their approach.
This article is for informational purposes only and does not constitute medical advice.
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