Cost-justification analysis of prenatal maternal serum alpha-feto protein screening

Cost and effectiveness of the California triple marker prenatal screening program

PURPOSE

To report the utilization of services offered and pregnancy outcomes for a unique statewide prenatal triple marker screening program and to present a cost-benefit analysis. A state population of 32 million with considerable ethnic and age distribution and with a wide variety of delivery systems providing prenatal care was considered. The entire pregnant population who appeared for care before 20 weeks gestation, approximately one-half million per year during the years of 1995 to 1997, was included in the study.

METHODS

Mandatory offering of serum testing, using alpha-fetoprotein from 1986 to 1995, and the addition of human chorionic gonadotropin and unconjugated estriol in 1995, with systematic follow-up of serum screen positives with ultrasound and amniocentesis. This study collected and analyzed the program data and reports of outcomes and collected similar information from the birth defects registry.

RESULTS

Triple marker serum screening was accepted by 67.4% of the women eligible and yielded an initial positive rate of 7.3%. More than 90% of the initially screen positive pregnancies were seen at a prenatal diagnostic center. After correction of gestational age, 71.3% had amniocentesis. The overall amniocentesis rate among women screened was 2.6%. The Program's detection rate was predicted to be 85% for neural tube defects, and, based on Monte Carlo modeling, was theoretically calculated to be 62% for Down syndrome. In practice, detection rates were 75% for neural tube defects and 41% for Down syndrome due to lower than expected amniocentesis acceptance rate. Nevertheless, at a 5% discount rate, the screening program was cost beneficial at a ratio of 2.69:1. The cost per case detected was $35,365 and per case prevented was $110,741.

CONCLUSION

It is possible to implement a cost-effective population-based screening in compliance with quality standards in a diverse ethnic population with a variety of health-care providers. Triple marker screening in the second trimester is a cost beneficial program even if utilization of all services is less than ideal.

Nondirectiveness in prenatal genetics: patients read between the lines

For decades questionnaires have been used to measure the cognitive and psychological effects of prenatal genetic testing, but little is known about why some women undergo testing and others decline. Research indicates that many factors influence decision making, including values and beliefs. What is often denied rather than recognized is that the professional and personal values and beliefs held by the health care provider influence the patient's decision. It is assumed that, if genetic services are delivered in a nondirective manner, patients will not be affected by the provider's personal and professional standpoint. The qualitative research data reported here challenge this assumption. Getting to know patients' moral understanding and patterns of ethical reasoning by listening to their personal stories is recommended as a better way for nurses to help patients to make informed and autonomous decisions about prenatal genetic screening or diagnostic tests.

Prenatal screening: when and for whom?

This report discusses the role of prenatal screening in preventing congenital abnormalities or, when prevention is not possible, in avoiding the conception or the birth of those who would have untreatable abnormalities. Women who are found by screening not to be immune to rubella can be safely vaccinated prior to pregnancy; those found to be at risk of having children with genetic disorders such as Tay-Sachs disease or thalassemia have the option of avoiding the conception of affected offspring. Screening during pregnancy permits the primary prevention of Rh disease and its sequelae when it results in the prophylactic administration of Rh-immune globulin to unsensitized Rh-negative women. Maternal serum alpha-fetoprotein screening identifies pregnant women who are at increased risk of carrying fetuses with neural tube defects or Down's syndrome, giving them the option of avoiding the birth of affected fetuses through abortion. Recombinant DNA technology will permit screening for many more genetic disorders as the disease-related genes and mutations are identified. For many of these disorders, the ability to predict the risk of disease will antedate preventive and therapeutic interventions by many years. During this lag phase, issues concerning the validity of the tests, the severity of the conditions for which screening is offered, the safety of the interventions, and the autonomy of the pregnant women in deciding to be screened are important.