A couple decided to have an offspring and went to the genetic counselor. The lady told that her younger sister died in childhood with Down syndrome. There is no other family history of the condition. What is the most appropriate counseling?

Down syndrome is generally random, so there is no increased risk to this couple.

If results of the woman's sister's karyotype cannot be found, the woman herself should have chromosomal analysis.

The pregnancy will be screened in the second trimester using alphafetoprotein, bhCG, and unconjugated estriol, which should be sufficient to detect Down syndrome if it has occurred.

Prenatal diagnosis should be done by chorionic villus sampling or amniocentesis.