This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Congenital malformations, Subject name: Gynaecology & Obstetrics
Recurrent aboion occurs in a woman, USG abdomen shows a non-echoic region in the central pa of the uterus. What is the probable diagnosis 
Select and explain. 
A. Arcuate uterus, B. Septate uterus, C. Bicornuate uterus, D. Unicornuate uterus
B: Septate uterus
Answer: B: Septate uterus 
Explanation: Septate uterus is most common It causes about 25% of spontaneous first trimester aboions 6% second trimester aboions Ref: Shaw Gynecology 17 e pg 72.