Gynaecology & Obstetrics First-Trimester Spontaneous Abortion d94c4ad4 Most common cause of spontaneous abortion is? A Chromosomal abnormality B Uterine malformations C Immunological D Infections High-Yield Explanation ANSWER: (A) Chromosomal abnormalityREF: Dutta 6th ed p. 159Most common cause of spontaneous abortion is chromosomal abnormality, trisomy of chromosome 16.