Chorionic vilious sampling is done in all except :
Ans. is c i.e. Neural tube defect "The indications of CVS and amniocentesis are usually the same, however disorders that specifically require analysis of amniotic fluid liquor such as neural tube defects are not amenable to prenatal diagnosis by CVS.- Indications of CVS 1. DNA analysis for diagnosis of genetic disorder without prior cultrue. a. Single gene disorder like Thalassemia major Hemophilia Duchene muscular dystrophy b. Inherited disorder of metabolism c. Determination of paternity 2. Early Karyotype is required Increased maternal age Previous aneuploidy Parental balanced translocation d Fragile X syndrome Early Amniocentesis at 12 to 14 weeks (or 10 to 14 weeks): Traditionally, genetic amniocentesis is performed at 16 weeks of gestation, and the results of the test become available in the eighteenth week. By this time, fetal movements may have already been noticed, making the option of termination of pregnancy. in the case of an abnormal result, distressing for most patents. Early amniocentesis is done at 12 to 14 weeks but can be performed as early as 10 weeks. Early amniocentesis is associated with increased risk of post procedural pregnancy loss, increased risk of positional foot deformities and membrane rupture.
Phenylketonuria
Down's syndrome
Neural tube defect
Thalassemia/ Sickle cell anemia