<prompt> A 35-year-old G4P3 at 18 weeks presents with sequential screening Dual and then triple marker screening of 1:170 for Down syndrome. You should do which of the following?Offer CVSAdvise her the risk is quite small for aneuploidyPerform a targeted ultrasoundOffer genetic counseling and perform Amniocentesis  <response>: At age 35 should the patient should be offered genetic counseling and Amniocentesis. CVS is not appropriate at 18 weeks gestation If required; the invasive test of choice here is Amniocentesis. 