Nub Theory is a popular early gender prediction method based on analyzing ultrasound images taken between 11 and 13 weeks of pregnancy. At this stage, all babies have a small protrusion between their legs known as the “nub” or genital tubercle. According to Nub Theory, the angle and direction of this nub in relation to the baby’s spine can suggest whether the baby is a boy or a girl. If the nub points upward at more than a 30-degree angle, it may indicate a boy; if it remains flat or points downward, it may suggest a girl. While not medically guaranteed, Nub Theory has become a fun and fascinating way for expectant parents to get an early peek into their baby’s gender.

Curious to know your baby’s gender before the 20-week scan?  Our Nub Theory Prediction Service offers a fun and early glimpse into your baby’s sex as early as 12 weeks! Using your ultrasound image, our trained analysts carefully assess the angle of the nub to provide a personalized and highly informed gender prediction. With years of experience and a passion for early pregnancy insights, we’re here to make your journey even more exciting. Submit your scan today and join thousands of parents who’ve discovered the magic of the nub!

The most accurate predictions are made between 12 and 13+6 weeks gestation. Submitting scans taken during this window ensures the nub is visible and developed enough for analysis.

We recommend a clear side profile (lateral) image of your baby, where the spine is visible and the baby is lying relatively flat. The better the image quality, the more accurate the prediction.

While Nub Theory is not 100% guaranteed, many studies and anecdotal evidence suggest it can be up to 85–95% accurate when used at the right time with a clear scan and proper analysis.

All predictions are made by experienced analysts who are trained in the principles of Nub Theory. We carefully assess each scan using multiple markers to provide the most informed prediction possible.

Nub Theory is not a substitute for medical testing. It is a fun and engaging way to get an early gender prediction, but it should not replace diagnostic procedures like NIPT or anatomy scans.

We offer standard and express options! Standard predictions are delivered within 48 hours, and express results are available in as little as 12 hours, depending on your chosen package.

Your personalized prediction, along with your custom drawing will be sent directly to your email.