Recurrent abortion in 1st trimester is most often due to:: (A) Chromosomal abnormalities, (B) Uterine anomaly, (C) Hormonal disturbance, (D) Infection
Answer is A. Most common cause of recurrent abortions:
1st trimester

Genetic factor/defective germplasm.
Most common type of chromosomal abnormality is balanced translocation.

2nd trimester 

Cervical incompetence