“The nub and skull theory is the fastest-growing gender prediction technique simply because it is so social," said Lisa Lum, a gender expert at parenting website Channel Mum, which commissioned ...

Parents-to-be are asking strangers to guess their baby’s sex by posting scan pictures online, in a wacky new craze sweeping the internet.

The nub theory is all to do with all that age-old guessing game of whether you're having a boy or girl. It is a concept that explores how a fetus's reproductive organs develop and not based around ...

The nub theory is based on predicting a child's gender at just 12 weeks Credit: Getty What is nub theory? The nub theory is also known as the angle of the dangle.

The nub theory is based on predicting a child's gender at just 12 weeks Credit: Getty What is nub theory? The nub theory is also known as the angle of the dangle.