Ever heard of the ‘nub theory’? It claims to reveal your baby’s sex at 12 weeks

There are plenty of old wives’ tales which claim to reveal the sex of your baby (you can read about them here) but there is one ‘test’ that claims to be a bit more accurate and involves your 12-week ultrasound. The ‘nub theory’ claims to be able to distinguish between a boy and girl as early as 12 weeks, which is quite the assertion considering that doctors usually tell the soon-to-be parents at around 20 weeks. At the 11-13 week stage, all babies have a ‘nub’ (it’s actually called the genital tubercle) between their legs and it is the position of this that gives an indication of the sex. Apparently (please note, this is not certain nor scientifically proven), if the nub is over 30 degrees in relation the spine, it’s a boy. If it’s under, it’s a girl. So basically, a steeper nub points towards a son while a gentler or downwards angle points towards a daughter. According to Netmums, the accuracy of the so-called test is 91 per cent at 12 weeks however for many it will not be possible to spot the nub on the scan. It is also open to interpretation in terms of the angle of the nub and can be difficult to get a clear image showing both the nub and the spine. In other words, it’s a fun theory to try out but don’t be placing any bets or painting the room based on what you think you see!