Heard of this one?

Parents-to-be typically (if they want to) learn whether they're having a boy or a girl at the 20-week scan mark but some impatient couples are turning to an unusual method to find out earlier. Medical experts largely wait until the halfway point in a pregnancy but some believe that there are 'signs' visible from as early as twelve weeks that'll help you make an educated guess. One thing to look out for, apparently, is the shape of the head. At twelve weeks, the male foetus' skull is said to be chunkier in shape and the brow ridge is a little more pronounced, while the chin might also be more square. For a girl, the chin will be slightly pointier while the brow ridge will be a little smaller. Another thing to look out for is the 'nub' between the legs. It's thought that if it's angled at more than 30 degrees, it's a boy while if it's less, it's a girl. Now, lots of parents are sharing photos of their baby scans on social media to get other people's opinions on what the baby's sex is. "The Nub and Skull theory is the fastest-growing gender prediction technique simply because it’s so social," Lisa Lum, a gender expert with parenting site ChannelMum.com told The Sun. Rather than a niche trend, the theory seems to be gaining traction. Research by ChannelMum shows that 45 per cent of 1,275 parents in a survey have used it to try and predict what they're having. "Three quarters of mums who try it say they like getting other people’s opinions on their child’s sex while 30 per cent see it as a worldwide craze they like to be part of," said Lisa. "While no non-medical technique is 100 per cent accurate, it’s fun and brings people together, which is exactly what children should do at all ages."