An economic evaluation of prenatal strategies for detection of trisomy 18, , ,

Objective: The objective of this study was to perform an economic evaluation of prenatal diagnostic strategies for women who are at increased risk for fetal trisomy 18 caused by either fetal choroid plexus cysts discovered in a conventional sonogram or an abnormal triple screen. Study Design: The prevalence of trisomy 18 in the presence of second-trimester fetal choroid plexus cysts and also in the presence of abnormal triple screen were made on the basis of previously reported studies. A cost/benefit analysis and cost-effectiveness determination of 3 strategies were performed: (1) no prenatal diagnostic workup of at-risk patients, (2) universal genetic amniocentesis of all at-risk patients, and (3) universal second-trimester targeted genetic ultrasonography of all at-risk patients with amniocentesis (for fetal karyotyping) reserved only for those with abnormal ultrasonography results. Results: The strategy of no prenatal diagnostic workup was the least expensive approach, costing $1,650,000 annually in the United States. The more costly approach was the strategy of universal amniocentesis for detecting fetal trisomy 18 in the presence of either second-trimester choroid plexus cysts or abnormal maternal serum screening, generating an annual cost of approximately $12 million and 40 fetal losses as a result of amniocenteses. The strategy of targeted genetic ultrasonography generated an annual cost of only $5 million and 8 fetal losses as a result of amniocenteses. Conclusions: Routine second-trimester amniocentesis in patients at increased risk for fetal trisomy 18 caused by either the presence of fetal choroid plexus cysts or abnormal triple screening is not justified from the cost/benefit point of view. (Am J Obstet Gynecol 1998;179:1220-4.)