174 Obstetrics and Gynecology Board Review •••
❍ What sign are the large arrows pointing to in this first trimester ultrasound?
Lambda sign or twin peaks sign.❍ What does this sign tell us about the chorionicity and amnionicity of this twin gestation?
It is dichorionic (and diamniotic).
❍ How would you describe the amnionicity and chorionicity of this first trimester pregnancy?
Trichorionic and triamniotic.