In completely non-technical speak, they look closely at what looks like a tube where the genitals are forming and pointing upwards most likely a boy, downwards for a girl. Our baby's was downwards. the technology has sure improved from when I was pg with DD. They were able to check the heart closely and other things that I remember having done at the 19 week scan last time. That was nearly six years ago!

I'm pleased for DD if she gets a sister.