Sometimes we just can’t wait ! And especially when you want to find out whether you are having a boy or girl

The Early Gender Scan can be carried out at the time of the Nuchal Scan at 11-13 weeks. If you would like to book an Early Gender Scan please click the blue button to the right of this article. 

Mr Penman, Fetal Medicine Specialist, has a long established reputation of Early Gender Scan assessments.     He has personally carried out over 56,000 scans and has been assessing gender for over 15 years, with the statistics below.

For the general scanning programme, please refer to the:

Baby Ultrasound Scan Programme

When Can I Have My Baby Gender/Wellbeing Scan?

  • There is an optimal time to achieve the highest accuracy in determining gender of your baby and get great scan pictures as a memory of that first moment you discovered your unborn baby’s gender.
  • A pregnancy gender scan cannot be carried out before 11 weeks. It is not possible to accurately scan and assess fetal gender before 11 weeks so gender assessment cannot done at the Viability (6 -10+ week) scan.
  • From 11-13+ weeks range, the gender can be  assessed by the angle of the genital tubercle (nub) relative to the spine. Genitalia in boys and girls develop from the same embryonic space.
  • It is possible to assess the gender of your baby when you come for a Nuchal Scan between 11 and 13+ weeks if you wish. The accuracy rises rapidly from the bottom end of the 11th week (75%) to the upper end of the 13th week (95%).
  • At 11 weeks –  75% accuracy. If you got this in an examination would be a pretty good percentage, but not when you want to know the gender of your baby! It means that on 25 occasions out of 100 scans, the gender of the baby will be wrong.

So at this stage, patience is the key.

  • At 12 weeks – accuracy goes up to 80-90%
  • At 13 weeks – accuracy is at 95%
  • The best time to have a Nuchal scan assessment is between 12 ½ weeks and 13 ½ weeks.
  • At 14/15 weeks – accuracy 97%
  • At 16 weeks  – accuracy is 99.9% – this means that 1 in 1000 assessments will be wrong.


How Can You Tell If I Am Having A Boy or A Girl When My Baby Is So Small?

At 12 weeks, the fetus is about 50mm (<2”) CRL (crown/ rump length – head to butt) and that is little more than the width of two 2pence coins! The nub at this gestation is about the size of a ‘pin head’!

Looking on ultrasound scan, Mr Penman is looking for two signs:

  • One is a ‘snail’ sign, which will show him that your baby is a boy.
  • The other is a ‘Big Mac’ sign which will indicated that your baby is a girl. However the absence of a penis cannot be taken as evidence that the fetus is a girl. But the ‘Big Mac’ denotes the lines of the labia are a very valid and accurate indication the fetus is a girl.


The Scan

Mr Penman will perform a thorough scan checking your baby’s wellbeing and growth, taking pictures and 4D movie at the same time. He will also perform the gender assessment. This will all be recorded in a wellbeing report for you and your doctor/midwife and all your image and movie will be saved onto a USB for you to take away.
The accuracy of the scan even at this gestation is still dependent on fetal position, amniotic fluid volume and maternal obesity (BMI).


Booking My Baby Early Gender/Nuchal  Scan – Cost £130

Your appointment will be with Mr Penman, Consultant Fetal Medicine Specialist.

Ring: Spire Alexandra Hospital – (01634) 687166



Baby Scan Booking Form and request an appointment there.

Length: 30 minutes


Wellbeing Report – (Full growth assessment appropriate for the stage of pregnancy)
Gender Assessment
2D Ultrasound Black +White prints (8-10)
3D / 4D views of your baby ( 4-5)
All images are saved onto a USB


Scan Preparation

As the scan requires Mr Penman to use a scan probe on your abdomen, two-piece clothing would be ideal.

A very full bladder is not usually necessary for this scan but try not to come with an empty bladder.

If Mr Penman should detect something on the scans that requires further investigation, he will talk you through the next necessary steps.