Hello - I work in a private scan clinic.
At 16 weeks it’s actually easier to see the sex than at 20 weeks. There is usually loads of space for baby to open their legs and for us to see.
A good sonographer will check to see if they can see the testicles on a boy and the labia and clitoris on a girl. They will also be able to use the Doppler to make sure no cord is trailing through the legs.
Ask for a potty shot. Ask them to label it.
Have a slush puppy or something cold, fizzy sweet to drink about 20 mins before you get there to wake baby up so they are moving about.
We find that it’s the sonogrphers at the hospital that get it wrong as they are not looking at the sex of babies all day like we are 😁
You will always get the odd story about the sex being wrong. Sometimes that’s because mum’s lied and baby is too young, cord has trapped a Willy, baby in really bad position, mums high BMI and sonogrsoher struggling to see baby at all.
But generally private scans around 15-17 weeks are much more correct than the 20
week scan.