Leftie or Righty - The Revelations of the 4D Ultrasound

A 4D ultrasound can pick up a lot of information, but did you know that whether your child is left-handed or right-handed is usually determined while in the womb?

Approximately 90% of us are right-handed, which means 10% are left-handed. Thanks to ultrasound, we have seen babies sucking their thumbs in the womb. Amazingly, 10% of babies in the womb prefer their left thumb and 90% of them prefer their right!

While elective ultrasounds like a 4D ultrasound aren’t performed until later, it has been observed at as early as 10 weeks gestation that a baby has a preference. This is the time when they start making independent arm movements. It has been observed that 90% of babies move their right arm more and 10% of babies move their left arm more. This is right in-tune with the percentages of us that are right- and left-handed.

So, if you are wondering whether your baby will be right-handed or left-handed, pay close attention to their movements during the ultrasound. If your baby sucks their left thumb or right thumb, that could be a good indicator of whether you have a lefty or righty. The same goes for which arm they prefer to move.