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 consider-able 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.
(C)1999The American College of Medical Genetics