Lambda sign or twin peak sign is seen in
High-Yield Explanation
The Lambda or Twin peak sign at 10-14 weeks of gestation demonstrate the high reliability of ultrasound examination in determining chorionicity in twin pregnancies. The "T sign" is really the absence of a twin-peak sign(or lambda (l) sign) and is used in ultrasound assessment of multifetal pregnancy. It refers tothe lack of chorion extending between the layers of the intewin membrane, denoting a monochorionic diamniotic pregnancy.