This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Obstetrics, Subject name: Gynaecology & Obstetrics
[{'content': 'A 38-year-old Primigravida who is pregnant after IVF , has a sonogram performed that shows Nuchal translucency of 5 mm at 12wks 4 days gestation. Which of the following is the only true statement? \nSelect and explain. \nA. The embryo has a high risk of neural tube defect, B. The embryo has a high risk of cardiac malformation, C. The nuchal translucency will enlarge by 20 weeks, D. If the embryo is aneuploid, the most likely diagnosis is Turner syndrome', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Nuchal translucency measured between 10 and 13 weeks is a useful marker for increased risk of chromosome abnormalities such as Down syndrome (not neural tube defects). The larger the nuchal translucency, the greater the risk of other adverse pregnancy outcomes, including fetal demise, cardiac abnormalities, and other genetic syndromes, even if the karyotype is normal. The nuchal translucency will almost always disappear by 15 weeks Increased nuchal translucency in aneuploid fetuses most likely indicates Down syndrome, followed by trisomy 18 and then Turner syndrome.', 'role': 'assistant'}]