How can you tell??

Su

I’m seeing so many people posting pictures of their ultrasounds with a side profile of their little nuggets with a caption that says something like “is this a boy or girl?” And they’re getting a bunch of responses. My question is how can you tell from a side profile shot? It’s not showing any identifiable parts relating to girls or boys (that I can tell, but I’ll be honest, ultrasounds are hard to decipher—everything looks a little like an alien/peanut hybrid). Is there something I don’t know? Or are people just 100% guessing?