This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Gynaecology & Obstetrics
A female with a family history of a genetic disorder became pregnant. Transabdominal chorionic villus sampling (CVS) can be done in: 
Select and explain. 
A. 7-9 weeks, B. 10 weeks to term, C. 9-11 weeks, D. 13-15 weeks
B: 10 weeks to term
Answer: B: 10 weeks to term 
Explanation: Chorionic villus sampling (CVS) is the second most common procedure for genetic prenatal diagnosis. This procedure is routinely performed transcervically at about 10-12 weeks of gestation and transabdominally from 10 weeks to term. Limb reduction defects are high when CVS was performed at less than 10 weeks of gestation. Ref: Textbook of Obstetrics by DC Dutta, 6th edition, Page 108.