Karyotyping of fetus can be done through all the following invasive methods except:
Amniocentesis
Cordocentesis
Chorionic villi sampling
Fetal skin biopsy
Fetal karyotyping can be done by Chorionic villi sampling Cordocentesis Amniocentesis Fetal skin biopsy is done to detect any chromosomal anomaly. It is done between 17-20 weeks to detect serious skin disorders like epidermolysis bullosa,oculocutaneous albinism. Ref: Williams Obs 23e pg 299-301.
General obstetrics