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Table 11-2

TestImplications of ResultsNursing Priorities
Cord blood type, group, and Coombs’ test Sample of cord blood is collected at delivery to determine newborn’s blood type and group (Rh positive or negative). Coombs’ test is done, especially for those whose mothers have type O or Rh-negative blood, or for neonates who are considerably jaundiced. Direct Coombs’ test will determine if antibodies are present in the neonate’s blood.
  1. Review prenatal record to determine risk for ABO and Rh incompatibility.
  2. Assess for jaundice. Age of the neonate in hours or days at the onset of jaundice is essential to diagnose underlying clinical causes.
  3. Provide support and information to the family regarding screening procedures.
Phenylketonuria (PKU)PKU is an autosomal recessive disease of protein synthesis in which the blood level of the amino acid phenylalanine becomes very high; the disorder results in mental retardation. If test is positive, retardation can be prevented through dietary control. Test is done with blood sample from neonate’s heel 24–36 hours after having milk. Usually repeat screening recommended, especially if discharged early.
  1. Review family history for incidence of inborn errors of metabolism.
  2. Observe neonate for: lethargy, apnea, poor feeding, poor muscle tone, jaundice, enlarged tongue, diarrhea, and unusual (musty) body odor.
  3. Provide support and information regarding screening procedures. Stress importance of follow-up testing.
HypothyroidismMass neonatal screening for hypothyroidism is a cost-effective measure for preventing mental retardation caused by thyroid dysfunction. Sample of neonate’s blood is taken for analysis (may be done with PKU analysis).
  1. Review family history for thyroid dysfunction.
  2. Provide support and information regarding screening procedures.
Galactosemia Galactosemia is an autosomal recessive disease in which the inborn error of metabolism involves the body’s inability to convert galactose to glucose. Surplus of galactose causes liver and brain damage. May be done with blood sample for PKU.
  1. Review family history for incidence of inborn errors of metabolism.
  2. Provide support and information to the family regarding screening procedures.
Sickle cell diseaseSickle cell is an autosomal recessive disorder occurring in certain ethnic groups, most commonly African American. Other ethnic origins may include: Mediterranean, Caribbean, Arabian, East Indian, and South and Central American. Disease is marked by crescent-shaped RBCs caused by defective hemoglobin. Severe, life-threatening attacks (crises) begin in childhood (fever and abdominal pain). Blood sample is taken after birth.
  1. Review family history for autosomal blood disorders, especially if member of high-risk ethnic group.
  2. Provide support and information to parents regarding genetic screening.
  3. Provide support and information to the family.
Tay-Sachs disease Tay-Sachs disease (TSD) is an autosomal recessive disease characterized by the absence of the enzyme hexosaminidase A (Hex-A). Especially common in people with eastern European (Ashkenazi) Jewish descent. Without Hex-A, a lipid GM2 ganglioside accumulates abnormally in cells, especially in the nerve cells of the brain.
The destructive process begins in the fetus early in pregnancy, although the disease is not clinically apparent until the child is several months old.
By the time a child with TSD is 3 or 4 years old, the nervous system is badly affected. Even with the best of care, all children with classical TSD die early in childhood, usually by age 5.
  1. Review family history for autosomal disorders, especially if member of high-risk ethnic group.
  2. Provide information about carrier screening.
  3. Provide support and information for the family.