External physical stimulation of the human fetus during episodes of low heart rate variation. Effect of vibratory acoustic stimulation on the duration of fetal heart rate monitoring tests. Antepartum fetal heart rate testing. XII. The effect of manual manipulation of the fetus on the nonstress test.
The effect of shaking the fetus through the maternal abdomen during episodes of low (nonreactive) fetal heart rate variation was studied in 10 healthy nulliparous women near term. Heart rate monitoring from an abdominal electrocardiogram was combined with real-time scanning for body movements and fetal breathing. In each fetus two episodes of low variation were examined, one during which external stimulation was performed and one as a control without stimulation. There were no differences between the groups, with or without stimulation, in the duration of the nonreactive trace or heart rate variation or in the incidence of breathing or body movements. Therefore, shaking the fetus during a nonreactive heart rate episode has no useful purpose. The results are comprehensible in the light of fetal and neonatal behavioral states. The ability of vibratory acoustic stimulation to shorten the duration of antepartum fetal heart rate monitoring was investigated by a randomized controlled trial. Vibratory acoustic stimulation did not shorten the overall duration of testing. This failure to improve the performance of antepartum monitoring appeared to result from prolonged accelerations, which complicated one third of the tests in which vibratory acoustic stimulation was employed. Further investigation is warranted using less profound methods of fetal stimulation. A prospective study of 790 patients was performed in order to examine the role of manual manipulation of the fetus in the nonstress test. The patients were assigned randomly to two groups based on the last two digits of their hospital number. The odd-numbered patients underwent manual manipulation of the fetus prior to the onset of the nonstress test; the even-numbered patients did not. There was no significant difference between the two groups with respect to the indications for testing and the total number of tests. There was no statistically significant difference between the two groups with respect to the ratio of reactive to nonreactive nonstress tests and the mean duration of testing. Simple manual manipulation of the fetus does not seem to change the outcome in antepartum fetal heart rate testing when the nonstress test is the primary one.
Manual fetal manipulation has not been shown to reduce the incidence of non-reactive cardiotocography. Trials of manual fetal manipulation should take into consideration that there have not been any benefits demonstrated as yet.
[Note: the two citations in the awaiting classification section may alter the conclusions of the review once assessed.]