A controlled trial of self-nonstress test versus assisted nonstress test in the evaluation of fetal well-being

OBJECTIVE: New portable devices have become available for home monitoring of fetal heart rates; these devices have the potential to immediately transmit these tracings to a medical facility. The null hypothesis of this study is the inability of mothers to perform their own nonstress tests (self-nonstress tests) and that such tests are not comparable to those performed by professional medical personnel (assisted nonstress tests). STUDY DESIGN: The feasibility of maternal self-testing was established in 50 high-risk patients followed by a controlled clinical trial conducted in 60 patients. The latter study represents the first controlled trial in which patients performed self-nonstress tests at their homes and transmitted the tracings via telecommunication to our perinatal unit. In all cases these patients came to our hospital within 60 minutes after the self-nonstress tests to have a perinatal nurse perform a second nonstress test. The pairs of self and assisted fetal heart rate tracings were independently reviewed by two investigators. RESULTS: The self and assisted tracing pairs were judged satisfactory for interpretation in 100% and 90%, respectively; self and assisted were interpreted by each examiner to be nonreactive in 20% and 14%, respectively. However, both examiners were unable to distinguish between tracings generated by assisted nonstress and self-nonstress tests. Furthermore, cost analysis revealed an estimated twofold savings with self-nonstress testing compared with the assisted nonstress test. CONCLUSION: Self-nonstress testing is a reliable and accurate method of antepartum fetal heart rate testing. This method of fetal assessment not only introduces a new approach to fetal surveillance with added convenience to patients, but may also significantly reduce medical cost without compromising the results of fetal testing. (Am J Obstet Gynecol 1992;166:489-92.)