Fetal heart rate monitoring in ambulatory and resting mothers

The nonstress test (NST) to assess fetal wellbeing is done over the course of 30 minutes with the patient lying in the semi-Fowler position. The test relates changes in fetal heart rate to fetal movement, and uterine contractions are also recorded. The purpose of this study was to determine whether the NST is affected by maternal ambulation, so that the patient must be lying down when it is performed. We did the NST during ambulation as well as with the patient reclining. There were no differences in fetal heart rate and/or uterine activity between the 2 tests. 50% of the women preferred the ambulatory method while 25% preferred reclining and 25% expressed no preference. We conclude, that the ambulatory NST is an acceptable alternative to the conventional test with the patient reclining.