system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
Most common abnormality in first trimester abortion
assistant
The correct answer is  A. i.e. (Defective genes) (161 - Dutta)* Genetic factor (50%) of early miscarriage are due to chromosomal abnormality in the conceptus. Autosomal trisomy is the commonest (50%) cytogenic abnormality in FIRST TRIMESTER*** Cervical incompetence (congenital or acquired) is the most common abnormality in SECOND TRIMESTER*** The cause of fetal death in ectopic pregnancy is postulated as vascular accident*** Most valuable diagnostic test in a case of suspected ectopic pregnancy is - Transvaginal USG**