My daughter is 16 weeks pregnant. She is in USA. She had been going for regular check ups from day1. Regular scannings were carried out. After 16 weeks the doctor informed that he/she forgot to carry out a test scanning which is supposed to be carried out after 12 weeks period and that there was a doubt expressed about the growth of Nasal bone. There were some blood and other tests carried out and they found the results satisfactory. Yet they wanted to go for another test of collecting some fluid from the womb for carrying another test. It appears that this has got some risk factors also. Would you advise such test?