This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: First-Trimester Spontaneous Abortion, Subject name: Gynaecology & Obstetrics
[{'content': 'Most common cause of spontaneous abortion is? \nSelect and explain. \nA. Chromosomal abnormality, B. Uterine malformations, C. Immunological, D. Infections', 'role': 'user'}, {'content': 'Answer: A \nExplanation: ANSWER: (A) Chromosomal abnormalityREF: Dutta 6th ed p. 159Most common cause of spontaneous abortion is chromosomal abnormality, trisomy of chromosome 16.', 'role': 'assistant'}]