The usefulness of a prenatal genetic questionnaire in genetic risk assessment

Objective: To evaluate a prenatal questionnaire as a genetic screen and as an aid in pre-amniocentesis genetic risk assessment. Methods: In a retrospective cohort study, charts were reviewed for 158 consecutive women of advanced maternal age referred for genetic counseling. Genetic risks identified by use of a questionnaire completed by 79 consecutive patients were compared with those risks identified by the referring physician, those identified during subsequent three-generation pedigree analysis, and to genetic risks identified by pedigree evaluation of 79 consecutive individuals who underwent genetic counseling without the aid of a questionnaire (controls). Results: Sixteen (20%) of the questionnaires revealed a previously unidentified genetic risk. The sensitivity and specificity of the questionnaire were determined to be 40.0 and 97.4%, respectively. Pedigree analysis alone (control group) identified significantly more at-risk pedigrees than did the questionnaire alone (34 versus 20%, P \u3c .05), but identified significantly fewer at-risk pedigrees than obtained from the study group patients who completed a questionnaire and pedigree evaluation (34 versus 50.6%, P \u3c .05). Of all 158 patients, 15.2% (n = 24) underwent additional testing on the basis of genetic risk assessment. There was no difference between the study and control groups in additional evaluations performed (P = 1.0). Conclusion: A three-generation pedigree is superior to a questionnaire in genetic risk assessment. The questionnaire was not sufficiently sensitive to serve independently as an adequate genetic screen or risk assessment tool and did not influence subsequent fetal evaluation. Assessment of the sensitivity and specificity of prenatal genetic questionnaires should be undertaken before their routine clinical use

The Importance of Genetic Counseling before Amniocentesis

OBJECTIVE: To determine the adequacy of genetic risk assessment among primary care providers and to evaluate the efficacy of genetic counseling before routine genetic amniocentesis. STUDY DESIGN: A retrospective cohort study was undertaken. Charts of 275 consecutive patients referred for genetic counseling and amniocentesis on the basis of advanced maternal age (AMA) were compared with charts of 103 consecutive patients referred for an abnormal maternal serum alpha-fetoprotein (MSAFP) finding. Pedigree information obtained during counseling of these patients was compared with the family histories charted by the referring physician. RESULTS: In 35.6% of pedigrees evaluated, a significant genetic risk was discovered during genetic consultation that had not been noted by the referring physician. Furthermore, 9.8% of AMA patients and 10.7% of patients with abnormal MSAFP results underwent additional genetic testing or screening on the basis of genetic counseling. Additional genetic testing of 0.8% of amniotic fluid specimens was done on the basis of the genetic risk assessment elicited during counseling. Although a significant difference in increased genetic risk was observed between the AMA and abnormal MSAFP groups (AMA 30.8% positive, MSAFP 48.5% positive; relative risk 0.81, confidence limit 0.70 to 0.93), no significant difference was observed between the two groups with regard to patient interventions (relative risk 0.97, confidence limit 0.79 to 1.21) or amniotic fluid testing (p = 0.57, not significant). CONCLUSIONS: The data support the importance of genetic counseling before amniocentesis. Furthermore, the findings support the relevancy and usefulness of genetic counseling in more accurately ascertaining genetic risk and in maximizing the benefits of genetic evaluation of patients seemingly at low risk for other genetic diseases