The population risk for Down syndrome is approximately 1 in 800 live bihs and the recurrence risk after the bih of an affected child is approximately 1-2 %. As the lady is already having a child with Down's , the doctor will advice her Chorionic Villous sampling (CVS) to assess fetal karyotype to check for Trisomy 21 can be done in the coming weeks to be sure of the diagnosis. Chorionic Villous sampling - Biopsy of chorionic villi is generally performed between 10 -13 weeks gestation. Most procedures are performed to assess fetal karyotype Numerous specialized genetic tests can also be performed by chorionic villus sampling The primary advantage of villus biopsy is that results are available earlier in pregnancy, allowing safer pregnancy termination. However, the aboion rates are 1-2% which is more than that of amniocentesis.