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 ...

BIRMINGHAM, Ala. “It’s going to be cold, and some pressure, O.K.?” The medical assistant guided the gelled ultrasound transducer across the pregnant woman’s belly. The patient, a 36-year ...