<prompt> Karyotyping of fetus can be done through all of the following invasive methods except:AmniocentesisCordocentesisChorionic villous samplingfetal skin biopsy  <response>: Invasive methods of prenatal diagnosis: In Chorion villus sampling, Amniocentesis and Cordocentesis fetal cells are obtained for karyotyping.Fetoscopy is done at 16-20 weeks, for visualization of fetal external anatomy and for fetal skin or muscle biopsy for diagnosis of genetic disorders Meckel-Gruber syndrome. Reference:Dutta,s Textbook of obstetrics 7th edition page no 494 