The nurse takes the history of a client, G2 P1, at her first prenatal visit. The client is referred to a genetic counselor, due to her previous child having a diagnosis of __________.

The scenario indicates that the client has a history of a previous child with a genetic condition, which warrants a referral to a genetic counselor during her first prenatal visit. Sickle cell anemia is a hereditary blood disorder characterized by the production of abnormal hemoglobin, leading to a variety of health complications. Because it is an autosomal recessive disorder, there is a significant genetic component that can be passed from parents to children.

In this context, a referral to a genetic counselor is particularly pertinent when there is a known hereditary condition in the family. Genetic counselors can provide valuable insights and risk assessments for prospective parents, especially if there is a known family history of a genetic disorder like sickle cell anemia. This helps the family understand their risks for having another child with the same condition or other related genetic issues.

The other options provided do not carry the same level of genetic concern or familial implications. Unilateral amblyopia can arise from various non-genetic factors, subdural hematoma is more commonly associated with trauma or injury and does not imply a genetic basis, and glomerular nephritis typically reflects a disease process rather than a genetic predisposition. Therefore, the referral to a genetic counselor in the case of a child with sickle cell anemia is justified