For instance, the Nuchal Translucency Scan, performed at 12 to 14 weeks, is an external scan. From this point in a pregnancy, internal scans are usually only performed if an external scan cant produce a clear image.

How do I prepare for my 12 week ultrasound?

You should drink two to three eight-ounce glasses of water one hour before your scheduled ultrasound. You shouldnt urinate before your ultrasound so you arrive at your appointment with a full bladder.

How accurate is gender ultrasound at 13 weeks?

The accuracy of determining your babys gender increases with how far along you are in the pregnancy. The accuracy can vary from 70.3% at 11 weeks to 98.7% at 12 weeks, and 100% at 13 weeks. Eleven weeks is the earliest that sex determination can be carried out with an ultrasound using a method called the nub theory.